@misc{Sommer_Robert_(1864–1937)_Tierpsychologie_1925, author={Sommer, Robert (1864–1937)}, copyright={Public Domain}, address={Leipzig}, howpublished={online}, year={1925}, publisher={Verlag von Quelle & Meyer}, language={ger}, title={Tierpsychologie}, type={Text}, URL={http://www.rcin.org.pl/Content/152239/PDF/WA488_187185_1496_Sommer-Tierpsychol.pdf}, keywords={Animal psychology - history, Animal psychology - basic concepts, Comparative psychopathology}, }