In memoriam : Prof. Ahto Kalja : 24.05.1950 - 22.10.2018Bubenko, Janis; Solvberg, Arne; Arnicans, Guntis; Borzovs, Juris; Čaplinskas, Albertas; Grundspeņķis, Janis; Haav, Hele-Mai; Kirikova, Marite; Lupeikiene, Audrone; Matulevičius, Raimundas; Robal, Tarmo; Vasilecas, Olegas; Lupeikiene, AudroneDatabases and information systems X : selected papers from the thirteenth International Baltic Conference, DB&IS 20182019 / p. v−vi : phot https://www.ester.ee/record=b5203991*est http://ebooks.iospress.nl/volume/databases-and-information-systems-x-selected-papers-from-the-thirteenth-international-baltic-conference-dbis-2018