• Effect of leaching pre-treatment on the char reactivity of pyrolyzed wheat straw [Electronic resource]Link, Siim; Arvelakis, Stelios; Paist, Aadu; Hupa, Mikko; Yrjas, Patrik; Külaots, Indrek17th European Biomass Conference & Exhibition : from Research to Industry and Markets : proceedings of the International Conference held in Hamburg, Germany, 29 June - 3 July 20092009 / p. 1113-1121 [DVD]
• Põlevkivi mineraalosa käitumine ülerõhul koldes : väitekiri on esitatud Tallinna Tehnikaülikooli tehnika magistrikraadi taotlemiseksKülaots, Indrek1995 https://www.ester.ee/record=b2078886*est
• Reactivity of the biomass chars originating from reed, douglas fir, and pineLink, Siim; Arvelakis, Stelios; Hupa, Mikko; Yrjas, Patrik; Külaots, Indrek; Paist, AaduEnergy & fuels2010 / 12, p. 6533-6539 https://pubs.acs.org/doi/abs/10.1021/ef100926v
• Reed as gasification fuel compared to woody fuelsLink, Siim; Kask, Ülo; Paist, Aadu; Arvelakis, Stelios; Hupa, Mikko; Yrjas, Patrik; Külaots, IndrekInternational Conference on the Utilization of Emergent Wetland Plants. Reed as a Renewable Resource, Greifswald, Germany, February 14-162013 http://mires-and-peat.net/media/map13/map_13_04.pdf
• Sintering and fouling characterization of ashes with high calcium oxide contentOts, Arvo; Parve, Teet; Skrifvars, Bengt-Johan; Hupa, MikkoProceedings of the 13th International Conference on Fluidized Bed Combustion. Vol. 21995 / [13] p.: ill
• Sulphation of Estonian and Israeli oil shale ashes under atmospheric and pressurized combustion conditionsKülaots, Indrek; Ots, Arvo; Yrjas, Patrik; Hupa, Mikko; Backman, P.Oil shale1997 / 3, p. 265-283: ill https://artiklid.elnet.ee/record=b2315277*est
• Sulphation of oil shale ash under atmospheric and pressurized combustion conditionsKülaots, Indrek; Yrjas, Patrik; Hupa, Mikko; Ots, Arvo1995 https://www.ester.ee/record=b2087107*est
• Sulphur capture by oil shale ashes under atmospheric and pressurized FBC conditionsYrjas, K.Patrik; Külaots, Indrek; Hupa, Mikko; Ots, ArvoProceedings of the 13th International Conference on Fluidized Bed Combustion. Vol. 21995 / [7] l.: ill
• The influence of temperature and gas composition on the sintering of Estonian oil shale ashParve, Teet; Skrifvars, Bengt-Johan; Ots, Arvo; Hupa, Mikko1994
• The sintering of Estonian oil shale ashesParve, Teet; Ots, Arvo; Skrifvars, Bengt-Johan; Hupa, MikkoOil shale1995 / 4, p. 341-356: ill
• The sintering tendency of ash from calcium rich oil shaleOts, Arvo; Parve, Teet; Skrifvars, Bengt-Johan; Hupa, MikkoJournal of the Institute of Energy1996 / Dec., p. 192-200