Students sleep while the professor is hard at work // Estonian Academy of Sciences yearbook 2019 : words and images. Facts and figures = Annales Academiae Scientiarum Estonicae. Tallinn : Argo Publishers, Estonian Academy of Sciences, 2020. p. 80 : ill. (Estonian Academy of Sciences year book : words and images : facts and figures = Annales Academiae Scientiarum Estonicae ; XXV(52)). https://www.ester.ee/record=b1218154*est