• A & A : riigi infosüsteemide erinumber2003 https://www.ester.ee/record=b1071898*est
• A multilevel modelling environment for machine elements designKalja, Ahto; Kindel, Kristiina; Tiidemann, TiitInternational Symposium on Machine Design OST 2001 : [Tallinn, Estonia, October 4-5, 2001] : abstracts2001 / [1] p. : ill
• A semantic method of automatic composition of e-government servicesMaigre, Riina; Grigorenko, Pavel; Haav, Hele-Mai; Kalja, AhtoDatabases and information systems : tenth international Baltic conference on databases and information systems : local proceedings, materials of doctoral consortium : Vilnius, Lithuania, July 8-11, 20122012 / p. 182
• A study on effective knowledge reuse in multi-platform web applications user interfacesMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoPICMET '15 Conference : Management of the Technology Age : August 2-6, 2015, Portland, Oregon, USA : conference bulletin2015 / p. 68
• AAMPA läbi aegade : [ettekanne TTÜs toimunud konverentsil, mis oli pühendatud TTÜ, TLÜ ja ITK toimetamisel ajakirja AAMPA 50. numbri ilmumiseks]Kalja, AhtoA & A2006 / lk. 5-8
• Administration of the state information system of the Estonian eGovernment [Electronic resource]Kalja, Ahto; Robal, Tarmo; Gailan, TriinPICMET '17 : Portland International Conference on Management of Engineering and Technology : Technology Management for the Interconnected World : proceedings2017 / p. 1-7 : ill. [USB] https://doi.org/10.23919/PICMET.2017.8125312
• Advances in Databases and Information Systems : 9th East European Conference, ADBIS 2005 : Tallinn, Estonia, September 12-15, 2005 : proceedings2005 http://www.ester.ee/record=b2068140*est
• Advances in Databases and Information Systems : proceedings of the 9th East-European Conference, ADBIS 2005 : Tallinn, September 12-15, 20052005 https://www.ester.ee/record=b2068111*est
• Ahto Kalja sõnavõtt : [akadeemikute Ilmar Öpiku ja Boris Tamme büstide avamisel akadeemikute alleel 17. sept. 2003]Kalja, Ahto85 aastat Tallinna Tehnikaülikooli2004 / lk. 51
• Ajutise teaduslik-tehnilise kollektiivi "Start" tööstKalja, AhtoArvutustehnika ja Andmetöötlus : A&A1989 / lk. 35-36 https://www.ester.ee/record=b1071940*est
• An ontology-based intelligent learning object for teaching the basics of digital logicRobal, Tarmo; Kann, Taavi; Kalja, Ahto2011 IEEE International Conference on Microelectronic Systems Education (MSE) : 5-6 June 2011, San Diego, CA, USA2011 / p. 106-107
• Analysing the web log to determine the efficiency of web systemsRobal, Tarmo; Kalja, Ahto; Põld, JanariDatabases and information systems : Seventh International Baltic Conference on Databases and Information Systems. Communications : Vilnius, Lithuania, July 3-6, 20062006 / p. 264-275
• Applying e-environments in teaching the basics of digital logicRobal, Tarmo; Kalja, AhtoProceedings MSE 2007 : 2007 IEEE International Conference on Microelectronic Systems Education : 3-4 June 2007, San Diego, CA2007 / p. 41-42 : ill https://ieeexplore.ieee.org/document/4231440/keywords#keywords
• Applying ICT for improving the study process [Electronic resource]Robal, Tarmo; Kalja, AhtoProceedings of the 18th EAEEIE Annual Conference : Praha, Czech Republic, 02-04.07.20072007 / ? p. [CD-ROM]
• Applying user domain model to improve Web recommendationsRobal, Tarmo; Kalja, AhtoDatabases and information systems : tenth international Baltic conference on databases and information systems : local proceedings, materials of doctoral consortium : Vilnius, Lithuania, July 8-11, 20122012 / p. 182 https://ebooks.iospress.nl/volumearticle/7673
• Applying user domain model to improve Web recommendationsRobal, Tarmo; Kalja, AhtoDatabases and information systems VII : selected papers from the tenth International Baltic Conference, DB&IS 20122013 / p. 118-131 https://doi.org/10.3233/978-1-61499-161-8-118 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-84873588757&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3233%2F978-1-61499-161-8-118%29&sessionSearchId=b54b8b263198aa2b467a2e833e85bb3b https://www.webofscience.com/wos/woscc/full-record/WOS:000349039600011
• Applying user profile ontology for mining web site adaption recommendationsRobal, Tarmo; Kalja, AhtoLocal Procedings of the 11th East-European Conference on Advances in Databases and Information Systems (ADBIS 2007)2007 / p. 126-135 https://www.researchgate.net/publication/221651686_Applying_User_Profile_Ontology_for_Mining_Web_Site_Adaptation_Recommendations
• Arvamused riigi infosüsteemide kohta : Ahto Kalja [küsimustele vastavad] Alo Koop, Rein Kuusik, ... [jt.]Kalja, Ahto; Koop, Alo; Kuusik, Rein, inform.A & A2003 / 3, lk. 77-83
• Automatic implementation-time usability evaluation for web user interfaces = Veebi kasutajaliidese kasutatavuse automaatne hindamine realisatsioonifaasisMarenkov, Jevgeni2019 https://www.ester.ee/record=b5231048*est
• CAD problem solving and technical systems modelling using the AI programming environmentsKalja, Ahto; Kotkas, Vahur; Tiidemann, TiitInformation Modelling and Knowledge Bases XII2001 / p. 284-290 https://www.researchgate.net/publication/221013967_CAD_Problem_Solving_and_Technical_Systems_Modelling_Using_the_AI_Programming_Environments
• CAD problem solving and technical systems modelling using the AI programming environmentsKalja, Ahto; Kotkas, Vahur; Tiidemann, TiitProceedings of the 10th European-Japanese Conference on Information Modelling and Knowledgfe Bases2000 / p. 284-290
• Calculation of gear drive by using AI methods in conceptual designSanko, Jelena; Tiidemann, Mart; Tiidemann, Tiit; Kalja, AhtoOST-99 Symposium on Machine Design : Stockholm, 30th Sept. - 1st Oct., 1999 : proceedings1999 / p. 21-27: ill
• Comparing software process improvement in Estonia and FinlandJaakkola, Hannu; Kalja, Ahto; Lepasaar, Marion; Varkoi, TimoBaltic ITAMPT review2001 / 3, p. 69-74
• Complementing ICT studies with learning objects on domain ontologiesRobal, Tarmo; Kruus, Helena; Kalja, AhtoProceedings of the 24th International Conference on European Association for Education in Electrical and Information Engineering : 30-31 May 2013, Chania, Greece2013 / p. 92-96 : ill
• A conceptual framework for software developing in mechanical CADKalja, Ahto; Tiidemann, Mart; Tiidemann, TiitOST-97 Symposium on Machine Design, Tallinn, Estonia, May 22-23, 1997 : proceedings1997 / p. 120-128: ill https://www.ester.ee/record=b1083704*est
• Conceptual web users' actions prediction for ontology-based browsing recommendationsRobal, Tarmo; Kalja, AhtoInformation systems development : towards a service provision society2009 / p. 121-129 https://link.springer.com/chapter/10.1007/b137171_13
• Creating interactive learning objects with web servicesRobal, Tarmo; Kalja, Ahto2009 EAEEIE annual conference : 20th Annual Conference of the European Association for Education in Electrical and Information Engineering : Valencia, Spain, June 22-24, 20092009 / [6] p
• Creativity trainings and technical education problems in CADKalja, Ahto; Tiidemann, Mart; Tiidemann, TiitProceedings of OST'05 Conference : Stockholm, October 20052006 / ? p
• Creativity trainings and technical education problems in CADKalja, Ahto; Tiidemann, Mart; Tiidemann, TiitProceedings of OST'05 Conference : Stockholm, Sweden, 20052005 / ? p
• Data exchange layer x-road in use for the third yearKalja, AhtoInformation Technology in Public Administration of Estonia : yearbook 20042005 / p. 19-24
• Databases and information systemsHaav, Hele-Mai; Kalja, Ahto2002 https://www.ester.ee/record=b1724800*est
• Databases and Information Systems : proceedings of the 11th International Baltic Conference, Baltic DB&IS 2014 : Tallinn, Estonia, 8-11 June, 20142014 http://www.ester.ee/record=b3088507*est
• Databases and information systems : proceedings of the Eighth International Baltic Conference, Baltic DBAMPIS 2008 : Tallinn, June 2-5, 20082008 http://www.ester.ee/record=b2374996*est
• Databases and information systems : proceedings of the Fifth International Baltic Conference : Baltic DB & IS 2002 : Tallinn, June 3-6, 20022002 http://www.ester.ee/record=b1641978*est
• Databases and information systems : proceedings of the Fifth International Baltic Conference : Baltic DB & IS 2002 : Tallinn, June 3-6, 20022002 https://www.ester.ee/record=b1641985*est
• Databases and information systems V : selected papers from the Eighth International Baltic Conference, DBAMPIS 2008Haav, Hele-Mai; Kalja, Ahto2009
• Databases and information systems VIII : selected papers from the Eleventh International Baltic Conference, DB&IS 20142014 https://www.ester.ee/record=b4447206*est
• Databases for systems with structural synthesis of programsHaav, Hele-Mai; Kalja, AhtoProc. of the Baltic Workshop on National Infrastructure Databases : problems, methods, experiences1994 / p. 185-196
• Design and automatic calculations of machine elementsTiidemann, Mart; Kalja, Ahto; Tiidemann, TiitEngineering Graphics BALTGRAF-11 : proceedings of the Eleventh International Conference : Tallinn, Estonia, June 9-10, 20112011 / p. 124-130 : ill
• Design-time web usability evaluation with guidelinerMakarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoComplex Systems Informatics and Modeling Quarterly (CSIMQ)2018 / art. 90, p. 90–109 : ill https://doi.org/10.7250/csimq.2018-15.05
• Dimensioning and tolerancing - some convenient methodsKalja, Ahto; Kindel, Kristiina; Tiidemann, Mart; Tiidemann, TiitEngineering Graphics BALTGRAF-6 : proceedings of the Sixth International Conference : Riga, Latvia, June 13-14, 20022002 / p. 65-70 : ill
• Early activities in the field of software process improvement in EstoniaKalja, Ahto; Oruaas, JaanBaltic IT review1999 / 4, p. 59-62
• e-EDU - an information system for e-learning servicesRobal, Tarmo; Kalja, AhtoProceedings of the Sixth International Baltic Conference : BalticDBAMPIS 2004 : Riga, June 3-6, 2004. Vol. 22004 / p. 143-154
• e-EDU - an information system for e-learning servicesRobal, Tarmo; Kalja, AhtoDatabases and information systems2005 / p. 288-298
• Eessõna Ilkka Hannula ja Risto Linturi raamatule "Sada nähtust 2000 - 2020"Kalja, AhtoA & A1999 / 1, lk. 40 https://artiklid.elnet.ee/record=b1000233*est
• Eesti ülikoolide ja infotehnoloogiafirmade koostööstJaakkola, Hannu; Kalja, Ahto; Meriste, MerikArvutimaailm1998 / 1, lk. 28-31: ill
• Eesti-Soome informaatika töörühm alustasKalja, AhtoArvutustehnika ja Andmetöötlus : A&A1989 / lk. 38 https://www.ester.ee/record=b1071940*est
• eGovernment in Estonia : best practicesKalja, Ahto; Reitsakas, A.; Saard, N.Technology management : a unifying discipline for melting the boundaries2005 / p. 500-506
• eGovernment services : How to develop them, how to manage them?Kalja, Ahto; Kindel, Kristiina; Kivi, Riina; Robal, TarmoProceedings of PICMET'07 : Management of Converging Technologies : Portland, OR, USA, 5-9. August 20072007 / p. 2795-2798 https://ieeexplore.ieee.org/document/4349620
• Ensuring large-scale semantic interoperability : the Estonian public sector's case studyHaav, Hele-Mai; Kalja, Ahto; Küngas, Peep; Luts, MartinDatabases and information systems V : selected papers from the Eighth International Baltic Conference, DBAMPIS 20082009 / p. 117-128 : ill
• Esimesed kümme X-tee aastatKalja, AhtoEesti infoühiskonna aastaraamat 2011/20122012 / lk. 78-80
• Estonian eGovernment services : lesson learnedKalja, Ahto; Põld, Janari; Robal, Tarmo; Vallner, Uuno; Viies, VladimirProceedings of PICMET'13 : Technology Management in the IT-Driven Services : [July 28-August 1, 2013, San Jose, California, USA]2013 / p. 562-568 : ill
• Estonian information technology policy in government, industry, and researchJaakkola, Hannu; Kalja, AhtoTechnology managements : strategies & applications1997 / 3, 299-307
• Evaluating Web systems on the basis of users' behavior modelingRobal, Tarmo; Kalja, AhtoInfo- ja kommunikatsioonitehnoloogia doktorikooli IKTDK kolmanda aastakonverentsi artiklite kogumik : 25.-26. aprill 2008, Voore külalistemaja2008 / p. 64-67 : ill
• Evaluations for improving web systems on the basis of users behaviour modellingRobal, Tarmo; Kalja, AhtoDatabases and information systems : proceedings of the Eighth International Baltic Conference, Baltic DBAMPIS 2008 : Tallinn, June 2-5, 20082008 / p. 229-240 : ill
• Expectations of software development practitioners for non-technical clientsOjastu, Deniss; Robal, Tarmo; Kalja, AhtoDatabases and information systems VIII : selected papers from the Eleventh International Baltic Conference, DB&IS 20142014 / p. 317-330 : ill https://doi.org/10.3233/978-1-61499-458-9-317 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-84911494323&origin=inward&txGid=74363347916161a81a2399f058ab8371 https://www.webofscience.com/wos/woscc/full-record/WOS:000362357700023
• A five step refactoring process : improving software design properlyPõld, Janari; Kalja, Ahto; Robal, TarmoInfo- ja kommunikatsioonitehnoloogia doktorikooli IKTDK kolmanda aastakonverentsi artiklite kogumik : 25.-26. aprill 2008, Voore külalistemaja2008 / p. 93-96 : ill
• A five step refactoring process : improving software design properlyPõld, Janari; Kalja, Ahto; Robal, TarmoDatabases and information systems : proceedings of the Eighth International Baltic Conference, Baltic DBAMPIS 2008 : Tallinn, June 2-5, 20082008 / p. 37-48 : ill
• A framework for improving web application user interfaces through immediate evaluationMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoDatabases and information systems IX : selected papers from the twelfth International Baltic Conference, DB&IS 20162016 / p. 283-296 : ill https://doi.org/10.3233/978-1-61499-714-6-283 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-85030170865&origin=inward&txGid=acb269d5faabd48da5294fdb8fbf10bf https://www.webofscience.com/wos/woscc/full-record/WOS:000390305200021
• From pencil to CAD and visual programmingTiidemann, Mart; Kalja, Ahto; Tiidemann, TiitEngineering Graphics BALTGRAF-8 : proceedings of the Eighth International Conference : Tallinn, Estonia, June 8-9, 20062006 / p. 131-136 : ill
• Guideliner : a tool to improve Web UI development for better usabilityMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoWIMS 2018 : 8th International Conference on Web Intelligence, Mining and Semantics, June 25–27 2018, Novi Sad, Serbia : proceedings2018 / art. 17, 9 p. : ill https://doi.org/10.1145/3227609.3227667 https://www.scopus.com/sourceid/11600154611 https://www.scopus.com/record/display.uri?eid=2-s2.0-85053484278&origin=inward&txGid=4cdc0f784f3f2916846048f2d6cf36ea
• Improving IT education in Estonian universitiesJaakkola, Hannu; Kalja, AhtoPICMET'97 : papers presented at PICMET'97 : Portland International Conference on Management of Engineering and Technology : Portland, Oregon, USA, July 27-31, 19971997 / p. 121-128
• Improving sophisticated self-service portal user interfaces : a study on user click behaviourMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoDatabases and Information Systems : proceedings of the 11th International Baltic Conference, Baltic DB&IS 2014 : Tallinn, Estonia, 8-11 June, 20142014 / p. 159-170 : ill
• Infotehnoloogia. Sõnastik. Osa 1, PõhiterminidHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1210955*est
• Infotehnoloogia. Sõnastik. Osa 2, Aritmeetika- ja loogikatehtedHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1210961*est
• Infotehnoloogia. Sõnastik. Osa 3, AparatuuritehnikaHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1708557*est
• Infotehnoloogia. Sõnastik. Osa 4, AndmekorraldusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1210974*est
• Infotehnoloogia. Sõnastik. Osa 5, AndmeesitusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1210985*est
• Infotehnoloogia. Sõnastik. Osa 6, Andmevalmendus ja andmekäitlusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211001*est
• Infotehnoloogia. Sõnastik. Osa 7, ProgrammeerimineHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2002 https://www.ester.ee/record=b1620201*est
• Infotehnoloogia. Sõnastik. Osa 8, TurvalisusHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1323628*est
• Infotehnoloogia. Sõnastik. Osa 9, AndmesideHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211010*est
• Infotehnoloogia. Sõnastik. Osa 10, Käitusmeetodid ja -vahendidHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211013*est
• Infotehnoloogia. Sõnastik. Osa 11, TöötlusseadmedHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211017*est
• Infotehnoloogia. Sõnastik. Osa 12, VälisseadmedHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211025*est
• Infotehnoloogia. Sõnastik. Osa 13, RaalgraafikaHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211072*est
• Infotehnoloogia. Sõnastik. Osa 14, Töökindlus, hooldatavus ja käideldavusHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1323632*est
• Infotehnoloogia. Sõnastik. Osa 15, ProgrammikeeledHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2001 https://www.ester.ee/record=b1536049*est
• Infotehnoloogia. Sõnastik. Osa 16, InfoteooriaHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211077*est
• Infotehnoloogia. Sõnastik. Osa 17, AndmebaasidHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211082*est
• Infotehnoloogia. Sõnastik. Osa 18, HajustöötlusHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2001 https://www.ester.ee/record=b1536056*est
• Infotehnoloogia. Sõnastik. Osa 19, AnaloogarvutidHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211085*est
• Infotehnoloogia. Sõnastik. Osa 20, SüsteemiarendusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211096*est
• Infotehnoloogia. Sõnastik. Osa 21, ProtsessiliidesedHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211102*est
• Infotehnoloogia. Sõnastik. Osa 22, KalkulaatoridHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1211104*est
• Infotehnoloogia. Sõnastik. Osa 23, TekstitöötlusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211107*est
• Infotehnoloogia. Sõnastik. Osa 24, Integraalne raalvalmistusHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211114*est
• Infotehnoloogia. Sõnastik. Osa 25, KohtvõrgudHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211120*est
• Infotehnoloogia. Sõnastik. Osa 26, Avatud süsteemide ühendamineHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211497*est
• Infotehnoloogia. Sõnastik. Osa 27, BürooautomaatikaHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211505*est
• Infotehnoloogia. Sõnastik. Osa 28, Intellektitehnika. Põhimõisted ja ekspertsüsteemidHanson, Vello; Agur, Ustus; Kalja, Ahto; Võhandu, Leo1998 https://www.ester.ee/record=b1211510*est
• Infotehnoloogia. Sõnastik. Osa 29, Intellektitehnika. Kõnetuvastus ja kõnesünteesHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2001 https://www.ester.ee/record=b1536063*est
• Infotehnoloogia. Sõnastik. Osa 30, RaalnägemineHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2003 https://www.ester.ee/record=b1763027*est
• Infotehnoloogia. Sõnastik. Osa 31, Intellektitehnika. TehisõpeHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo1999 https://www.ester.ee/record=b1323638*est
• Infotehnoloogia. Sõnastik. Osa 32, ElektronpostHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2002 https://www.ester.ee/record=b1620212*est
• Infotehnoloogia. Sõnastik. Osa 33, Hüpermeedium ja multimeediumHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2003 https://www.ester.ee/record=b1763032*est
• Infotehnoloogia. Sõnastik. Osa 34, Intellektitehnika. NeurovõrgudHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2001 https://www.ester.ee/record=b1536069*est
• Infotehnoloogia. Sõnastik. Osa 35, VõrgundusHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2003 https://www.ester.ee/record=b1763034*est
• Infotehnoloogia. Sõnastik. Osa 37, VirtuaalreaalsusHanson, Vello; Tavast, Arvi; Kalja, Ahto; Võhandu, Leo2003 https://www.ester.ee/record=b1763036*est
• Infotehnoloogiaüritustel RiiasKalja, Ahto; Penjam, JaanA & A1998 / 3, lk. 58-60
• Interactive hands-on tools as learning objects on web servicesRobal, Tarmo; Kalja, Ahto2009 International Conference on Microelectronic Systems Education : San Francisco, CA, USA, 25-27 July, 20092009 / p. 73-76
• IT innovation is the first step on the way to the information societyJaakkola, Hannu; Kalja, AhtoProceedings PICMET'01 : Portland, Oregon, USA, 2001 : book of summaries. Vol. 12001 / p. 490
• IT strategies and government IT policy in Estonia - changes and foreign influencesKalja, Ahto; Jaakkola, HannuTechnological innovation and global challenges : proceedings of the European Conference on Management of Technology, Aston University, Birmingham, UK1995 / p. 876-883
• Key success factors of a regional software process improvement programLepasaar, Marion; Kalja, Ahto; Varkoi, T.; Jaakkola, HannuProceedings PICMET'01 : Portland, Oregon, USA, 2001 : book of summaries. Vol. 12001 / p. 432 https://ieeexplore.ieee.org/document/952341
• Learning from users for a better and personalized web experienceRobal, Tarmo; Kalja, Ahto2012 Proceedings of PICMET '12 : Technology Management for Emerging Technologies2012 / p. 2179-2188 : ill
• Läti keelel on teadustöös suurem roll kui eesti keelelHaav, Hele-Mai; Kalja, Ahto; Nõges, KrõõtMente et Manu2014 / lk. 16-17 : fot https://artiklid.elnet.ee/record=b2674038*est
• Making use of personalized web services in the study processRobal, Tarmo; Kalja, AhtoBEC 2008 : 2008 International Biennial Baltic Electronics Conference : proceedings of the 11th Biennial Baltic Electronics Conference : Tallinn University of Technology : October 6-8, 2008, Tallinn, Estonia2008 / p. 211-212 : ill
• Making web users' domain models explicit by applying ontologiesRobal, Tarmo; Haav, Hele-Mai; Kalja, AhtoAdvances in Conceptual Modeling - Foundations and Applications : ER 2007 Workshops CMLSA, FP-UML, ONISW, QoIS, RIGiM, SeCoGIS : Auckland, New Zealand, November 5-9, 2007 : proceedings2007 / p. 170-179 https://link.springer.com/content/pdf/10.1007/978-3-540-76292-8_20.pdf
• Managing knowledge in Web portals for improved customer loyalty and satisfactionRobal, Tarmo; Kalja, AhtoProceedings of PICMET'13 : Technology Management in the IT-Driven Services : [July 28-August 1, 2013, San Jose, California, USA]2013 / p. 1207-1216 : ill
• Managing software engineering competences with domain ontology for customer and team profiling and trainingRobal, Tarmo; Ojastu, Deniss; Kalja, Ahto; Jaakkola, HannuPICMET '15 : proceedings : Management of the Technology Age2015 / p. 1369-1376 : ill http://dx.doi.org/10.1109/PICMET.2015.7273171
• Managing software engineering competences with domain ontology for customer and team profiling and trainingRobal, Tarmo; Ojastu, Deniss; Kalja, Ahto; Jaakkola, HannuPICMET '15 Conference : Management of the Technology Age : August 2-6, 2015, Portland, Oregon, USA : conference bulletin2015 / p. 62
• Mapping of SQL relational schemata to OWL ontologiesAstrova, Irina; Kalja, AhtoProceedings of the 6th WSEAS International Conference on Applied Informatics and Communications : Crete Island, Greece, August 18-20, 20062006 / p. 375-380 https://dl.acm.org/doi/abs/10.5555/1366421.1366487
• Masinaelementide raalprojekteerimise paketid "Expertprizis"Kalja, Ahto; Tiidemann, TiitArvutustehnika ja Andmetöötlus1988 / lk. 13-17 : ill https://www.ester.ee/record=b1071940*est
• MasinprojekteerimineKalja, Ahto; Tiidemann, Tiit; Tõugu, Enn1991 http://www.ester.ee/record=b1190460*est
• Mining and modelling web user engagement : a survey on academic sites for framework establishment [Electronic resource]Robal, Tarmo; Kalja, AhtoPICMET '16 : Portland International Conference on Management of Engineering and Technology : proceedings. Technology Management for Social Innovation2016 / p. 1942-1952 : ill. [USB] https://doi.org/10.1109/PICMET.2016.7806759
• A model for users' action prediction based on locality profilesRobal, Tarmo; Kalja, AhtoInformation systems development : challenges in practice, theory and education. Volume 12009 / p. 169-182 https://link.springer.com/chapter/10.1007/978-0-387-68772-8_14
• Modernization of the e-government in EstoniaKalja, Ahto; Põld, Janari; Robal, Tarmo; Vallner, UunoProceedings of PICMET '11 : Technology Management in the Energy Smart World (PICMET) : July 31 - August 4, 2011, Portland, Oregon USA2011 / p. 3151-3157 : ill
• Moving Hadoop to the Cloud for Big Data AnalyticsAstrova, Irina; Koschel, Arne; Heine, Felix; Kalja, AhtoDatabases and information systems X : selected papers from the thirteenth International Baltic Conference, DB&IS 20182019 / p. 195-209 https://doi.org/10.3233/978-1-61499-941-6-195 https://www.ester.ee/record=b5203991*est https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-85063345850&origin=inward&txGid=a2927f1085e12166d4ea81c23072ace0 https://www.webofscience.com/wos/woscc/full-record/WOS:000625446400013
• Moving studies to e-environments : a case studyRobal, Tarmo; Kalja, AhtoCurrent Developments in Technology-Assisted Education : Badajoz, Spain. Vol. II2006 / p. 936-940
• A multilevel modelling environment for machine elements designKalja, Ahto; Kindel, Kristiina; Tiidemann, Mart; Tiidemann, TiitOST-01 Symposium on Machine Design : Tallinn, Estonia, October 4-5, 2001 : proceedings2001 / p. 45-50 : ill https://www.ester.ee/record=b1642353*est
• Mõõtahelate ja istude koosarvutamisestTiidemann, Tiit; Kalja, AhtoTallinna Tehnikakõrgkooli Toimetised2004 / lk. 61-65 : ill
• New generations of Estonian eGovernment componentsKalja, Ahto; Robal, Tarmo; Vallner, UunoPICMET '15 : proceedings : Management of the Technology Age2015 / p. 625-631 : ill http://dx.doi.org/10.1109/PICMET.2015.7273002
• New generations of Estonian eGovernment componentsKalja, Ahto; Robal, Tarmo; Vallner, UunoPICMET '15 Conference : Management of the Technology Age : August 2-6, 2015, Portland, Oregon, USA : conference bulletin2015 / p. 93
• A novel approach to mapping SQL relational schemata to OWL ontologiesAstrova, Irina; Kalja, AhtoWSEAS transactions on information science and applications2006 / 3, p. 2215-2222
• On integration of object-oriented applications with relational databasesAstrova, Irina2003 http://www.ester.ee/record=b1833107*est
• On proving the concept of an ontology aided software refactoring toolPõld, Janari; Robal, Tarmo; Kalja, AhtoDatabases and information systems VII : selected papers from the tenth International Baltic Conference, DB&IS 20122013 / p. 84-94 https://doi.org/10.3233/978-1-61499-161-8-84 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-84873584579&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3233%2F978-1-61499-161-8-84%29 https://www.webofscience.com/wos/woscc/full-record/WOS:000349039600008
• On proving the concept of an ontology aided software refactoring toolPõld, Janari; Robal, Tarmo; Kalja, AhtoDatabases and information systems : tenth international Baltic conference on databases and information systems : local proceedings, materials of doctoral consortium : Vilnius, Lithuania, July 8-11, 20122012 / p. 179 https://www.researchgate.net/publication/287294774_On_proving_the_concept_of_an_ontology_aided_software_refactoring_tool
• Ontology design for automatic evaluation of web user interface usability [Electronic resource]Robal, Tarmo; Marenkov, Jevgeni; Kalja, AhtoPICMET '17 : Portland International Conference on Management of Engineering and Technology : Technology Management for the Interconnected World : proceedings2017 / p. 1-8 : ill. [USB] https://doi.org/10.23919/PICMET.2017.8125425
• Overview of SPI activities in EstoniaKalja, Ahto; Oruaas, JaanProceedings of the EuroSPI'99 conference : Learn from the Past - Experience the Future : Pori, Finland, 25.-27. October 19991999 / p. 8.41-8.47
• Perceptions of software development practitioners on client learningOjastu, Deniss; Robal, Tarmo; Kalja, AhtoDatabases and Information Systems : proceedings of the 11th International Baltic Conference, Baltic DB&IS 2014 : Tallinn, Estonia, 8-11 June, 20142014 / p. 397-406
• PrefaceHaav, Hele-Mai; Kalja, Ahto; Robal, TarmoDatabases and information systems VIII : selected papers from the Eleventh International Baltic Conference, DB&IS 20142014 / p. v
• PRIZ-pere tarkvarasüsteemidKalja, AhtoArvutustehnika ja Andmetöötlus1988 / lk. 21-24 https://www.ester.ee/record=b1071940*est
• Professor Ahto Kalja kõne rektor Boris Tamme rinnakuju avamisel : [17. sept. 2003 Akadeemikute alleel]Kalja, AhtoTallinna Tehnikaülikooli aastaraamat 20032004 / lk. 55-56
• Projekti X-tee arengusammudKalja, AhtoA & A2003 / 3, lk. 15-23 https://artiklid.elnet.ee/record=b1013459*est
• Public e-service projects in EstoniaKalja, Ahto; Vallner, UunoDatabases and information systems : proceedings of the Fifth International Baltic Conference : Baltic DB & IS 2002 : Tallinn, June 3-6, 2002. Vol. 22002 / p. 143-153
• Refactoring - key to success for constantly developed projectsPõld, Janari; Kalja, Ahto; Robal, TarmoInformation modelling and knowledge bases XXVIII2017 / p. 13-22 https://doi.org/10.3233/978-1-61499-720-7-13 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-85002926135&origin=inward&txGid=ff9869b44c9b4de299fc0d779a5d3dea https://www.webofscience.com/wos/woscc/full-record/WOS:000402391600002
• Refactoring - key to success for constantly developed projects [Electronic resource]Põld, Janari; Kalja, Ahto; Robal, TarmoProceedings of the 26th International Conference on Information Modelling and Knowledge Bases - EJC 2016 : June 6-10, 2016, Tampere, Finland2016 / p. 15-24. [USB]
• Riigi andmekogude moderniseerimise programm (X-tee)Kalja, AhtoInfotehnoloogia avalikus halduses : aastaraamat 20012001 / lk. 45-48 : ill
• SaateksKalja, AhtoArvutustehnika ja Andmetöötlus1992 / 2, lk. [1]
• Scalable Hadoop-based infrastructure for big data analyticsAstrova, Irina; Koschel, Arne; Heine, Felix; Kalja, AhtoDatabases and Information Systems : 13th International Baltic Conference, DB&IS 2018, Trakai, Lithuania, July 1-4, 2018 : proceedings2018 / p. 233-242 https://doi.org/10.1007/978-3-319-97571-9_19 https://www.scopus.com/sourceid/17700155007 https://www.scopus.com/record/display.uri?eid=2-s2.0-85052904147&origin=inward&txGid=4b5951f429aa3ca528e810f1d74e6e86
• A semantic method of automatic composition of E-government servicesMaigre, Riina; Grigorenko, Pavel; Haav, Hele-Mai; Kalja, AhtoDatabases and information systems VII : selected papers from the Tenth International Baltic Conference, DB&IS 20122013 / p. 204 - 217 https://doi.org/10.3233/978-1-61499-161-8-204 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-84873589293&origin=resultslist&sort=plf-f&src=s&sot=b&sdt=b&s=DOI%2810.3233%2F978-1-61499-161-8-204%29&sessionSearchId=ea143ef021606db856247536fe1f23a3 https://www.webofscience.com/wos/woscc/full-record/WOS:000349039600017
• Semantilise koosvõime arhitektuur riigi infosüsteemisHaav, Hele-Mai; Kalja, Ahto; Küngas, Peep; Luts, MartinA & A2008 / lk. 32-42 : ill https://artiklid.elnet.ee/record=b1022736*est
• Small knowledge-based CAD systemsKalja, Ahto; Pahapill, JaakInformation modelling and knowledge bases 31992 / p. 347-356 https://digikogu.taltech.ee/et/Item/0b81d45e-2526-40af-a28d-25ffb6232807
• Storing OWL ontologies in SQL relational databasesAstrova, Irina; Korda, Nahum; Kalja, AhtoInternational journal of electrical, computer, and systems engineering2007 / 4, p. 242-247 https://zenodo.org/records/1071690
• Storing OWL ontologies in SQL relational databasesAstrova, Irina; Korda, Nahum; Kalja, AhtoProceedings of World Academy of Science, Engineering and Technology (WASET) : International Conference on Computer, Electrical, and Systems Science, and Engineering (CESSE) : Berlin, Germany, 20072007 / p. 169-172 https://www.researchgate.net/publication/242756222_Storing_OWL_ontologies_in_SQL_relational_databases
• A study on effective knowledge reuse in multi-platform web applications user interfacesMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoPICMET '15 : proceedings : Management of the Technology Age2015 / p. 1351-1361 : ill https://doi.org/10.1109/PICMET.2015.7273083
• A study on immediate automatic usability evaluation of web application user interfacesMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoDatabases and Information Systems : 12th International Baltic Conference, DB&IS 2016, Riga, Latvia, July 4-6, 2016 : proceedings2016 / p. 257-271 : ill https://doi.org/10.1007/978-3-319-40180-5_18 https://www.scopus.com/sourceid/17700155007 https://www.scopus.com/record/display.uri?eid=2-s2.0-84978973676&origin=inward&txGid=aaf99f0c3e1921716c44ff287cd0a290 https://www.webofscience.com/wos/woscc/full-record/WOS:000389806000018
• A study on user click behaviour for WIS user interface improvementsMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoDatabases and information systems VIII : selected papers from the Eleventh International Baltic Conference, DB&IS 20142014 / p. 173-186 : ill https://doi.org/10.3233/978-1-61499-458-9-173 https://www.scopus.com/sourceid/19500157321 https://www.scopus.com/record/display.uri?eid=2-s2.0-84911462525&origin=inward&txGid=552223810b398e7eedee0bde2abf2701 https://www.webofscience.com/wos/woscc/full-record/WOS:000362357700013
• Studying the incorrect user behaviour in sophisticated self-service portal user interfacesMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoProceedings of the 8th Annual Conference of the Estonian National Doctoral School in Information and Communication Technologies : December 5-6, 2014, Rakvere2014 / p. 71-74 : ill
• Supporting mechanical design with visual programming in the NUT environmentKalja, Ahto; Tiidemann, TiitOST-98 Symposium on Machine Design, Oulanka, Finland, October 1-3, 1998 : proceedings1998 / p. 163-172: ill
• System integration process of government information systemsKalja, AhtoThe proceedings of PICMET'03 : Portland, Oregon, USA, 20032003 / [6] p
• Teadusseminaril JaapanisKalja, AhtoArvutustehnika ja Andmetöötlus1992 / 4, lk. 37-40
• Teine rahvusvaheline infotehnoloogiakonverents "Eesti infomaastik '99"Kalja, AhtoA & A1999 / 4, lk. 49-51
• Tele-education projects in the broadband network in EstoniaKalja, Ahto; Ots, Avo; Penjam, JaanBaltic IT review1999 / 3, p. 65-68
• The co-operation of universities and IT companies in EstoniaJaakkola, Hannu; Kalja, Ahto; Meriste, MerikPioneering New Technologies : Management Issues and Challenges in the Third Millennium : IEMC '98 proceedings, International Conference on Engineering and Technology Management : October 11 to 13, 1998, San Juan, Puerto Rico, USA1998 / p. 202-206
• The Estonian semantic interoperability initiative in public sectorLuts, Martin; Haav, Hele-Mai; Küngas, Peep; Vallner, Uuno; Kalja, Ahto; Arula, KalleDatabases and information systems : proceedings of the Eighth International Baltic Conference, Baltic DBAMPIS 2008 : Tallinn, June 2-5, 20082008 / p. 103-113
• The first ten years of X-roadKalja, AhtoEstonian information society yearbook 2011/20122012 / p. 78-80
• The future of educating IT professionals in EstoniaJaakkola, Hannu; Kalja, Ahto; Meriste, MerikBaltic IT review1998 / 3, p. 50-53: ill
• The International IT & Telecommunications Conference "Estonian Infoscape 1998"Kalja, AhtoBaltic IT review1998 / 3, p. 15-16: ill
• The most important trends in machine designKalja, Ahto; Tiidemann, Mart; Tiidemann, TiitOST-03 Symposium on Machine Design2003 / p. 212-219 : ill
• The most prominent software development concepts cited in IT professionals' blogsOjastu, Deniss; Robal, Tarmo; Kalja, AhtoPerspectives in business informatics research : 14th International Conference, BIR 2015, Tartu, Estonia, August 26-28, 2015 : proceedings2015 / p. 197-212 https://doi.org/10.1007/978-3-319-21915-8_13 https://www.scopus.com/sourceid/17500155101 https://www.scopus.com/record/display.uri?eid=2-s2.0-84951267009&origin=inward&txGid=5569f37124f3701f453bd4c58072573a
• The Second International Information Technologies and Telecommunications Conference "Estonian Infoscape 1999"Kalja, AhtoBaltic IT review1999 / 2, p. 15-16
• The service-oriented environment of government databases and information systems in EstoniaKalja, Ahto; Kindel, Kristiina; Kivi, RiinaBaltic ITAMPT review2004 / 3, p. 7-11 https://artiklid.elnet.ee/record=b2026367*est
• The X-road : a key interoperability component within the state information systemKalja, AhtoInformation technology in public administration of Estonia : yearbook 20072008 / p. 19-22
• The X-road project : a project to modernize Estonia's national databasesKalja, AhtoBaltic ITAMPT review2002 / 1, p. 47-48
• A tool for design-time usability evaluation of web user interfacesMarenkov, Jevgeni; Robal, Tarmo; Kalja, AhtoAdvances in databases and information systems 21st European Conference, ADBIS 2017 Nicosia, Cyprus, September 24-27, 2017 : proceedings2017 / p. 394-407 : ill https://doi.org/10.1007/978-3-319-66917-5_26 https://www.scopus.com/sourceid/25674 https://www.scopus.com/record/display.uri?eid=2-s2.0-85030183638&origin=inward&txGid=be09d358e2a39dd209483ee9cb7a5475 https://www.webofscience.com/wos/woscc/full-record/WOS:000463611400026
• Tools and Techniques for event log analysisVaarandi, Risto2005 https://www.ester.ee/record=b2045293*est
• Towards adaptive web - analysing and recommending web users' behaviour = Veebikasutajate käitumise analüüs ja soovitused adaptiivse veebi loomiseksRobal, Tarmo2012 https://www.ester.ee/record=b2862251*est
• Towards information society : Estonian case studyKalja, Ahto; Robal, Tarmo; Vallner, UunoProceedings of PICMET'09 : Portland International Conference on Management of Engineering & Technology, 2009 : Portland, Oregon, USA, August 2-6, 20092009 / p. 3218-3225 : ill
• Towards the semantic web : extracting OWL ontologies from SQL relational schemataAstrova, Irina; Kalja, AhtoProceedings of the IADIS International Conference WWW/Internet 2006 (ICWI) : Murcia, Spain, 2006, October 5-8. Volume 22006 / p. 62-66
• TRIZ and artificial intelligent software in the conceptual designKalja, Ahto; Tiidemann, TiitThe Sixth Annual Conference of the Altshuller Institute for TRIZ Studies : TRIZCON2004 : Seattle, Washington, April 25-27, 20042004 / p. 29-1 - 29-7
• TRIZ and ExpertPRIZ type AI software in engineering and educationTiidemann, Tiit; Kalja, AhtoWorld Conference TRIZ Future 2005 : November 16 to 18, 2005, Graz, Austria2005 / p. 175-181 : ill
• Using software with AI elements for conceptual design of machine elementsTiidemann, Mart; Kalja, Ahto; Tiidemann, Tiit; Tõugu, EnnProceedings of the 8th International Conference of DAAAM Baltic Industrial Engineering, 19-21st April 2012, Tallinn, Estonia. 12012 / p. 357-360 : ill
• Web systems evaluation on users' behaviour modellingRobal, Tarmo; Kalja, AhtoDatabases and information systems V : selected papers from the Eighth International Baltic Conference, DBAMPIS 20082009 / p. 41-52 : ill
• X-road - one of the cornerstones of the state information systemKalja, AhtoInformation technology in public administration of Estonia : yearbook 20062007 / p. 35-43
• X-road data traffic open for the second yearKalja, AhtoInformation technology in public administration of Estonia : yearbook 20032004 / p. 32-37
• X-tee andmeliiklus on avatud teist aastatKalja, AhtoInfotehnoloogia avalikus halduses : aastaraamat 20032003 / lk. 32-35 https://artiklid.elnet.ee/record=b2125800*est
• X-tee areng ja teenusedKalja, AhtoInfotehnoloogia avalikus halduses : aastaraamat 20022002 / lk. 24-26
• X-tee on üks infoühiskonna arendusplaani nurgakividest Eestis [Elektrooniline teavik]Kalja, AhtoInfotehnoloogia avalikus halduses : aastaraamat 20062006 / lk. 26-29 https://www.ester.ee/record=b1696552*est
• X-tee pakub teenustele orienteeritud arhitektuuriKalja, AhtoInfotehnoloogia avalikus halduses : aastaraamat 20072007 / lk. 34-36
• Индивидуальные базы данных для технологического проектированияKalja, AhtoАвтоматизация технологического проектирования процессов механической обработки1980 / с. 29-36
• Инструментальная система программирования ЕС ЭВМ (ПРИЗ)Kahro, Milvi; Kalja, Ahto; Tõugu, Enn1981 https://www.ester.ee/record=b1547892*est
• Инструментальная система программирования ЕС ЭВМ (ПРИЗ)Kahro, Milvi; Kalja, Ahto; Tõugu, Enn1988 https://www.ester.ee/record=b1547903*est
• Интеграция расчетного и конструкторского проектирования на персональных ЭВМKalja, Ahto; Toomsalu, Toomas; Üksti, LembitМетодология проектирования САПР: тезисы докладов VI Всесоюзного совещания по автоматизации проектирования электротехнических устройств : 14-17 октября 1985 года, Таллин1985 / с. 152-154
• МашиностроениеGrossschmidt, Gunnar; Pääsuke, Jüri; Viktorova, N.H.; Eljas, Olev; Pruuden, Juhan; Küttner, Rein; Kalja, Ahto; Papstel, Jüri; Riives, Jüri1980 https://www.ester.ee/record=b1264085*est