Search for: [Subject and Keywords = Animal psychology \- history] OR [Subject and Keywords = Animal psychology \- basic concepts] OR [Subject and Keywords = Comparative psychopathology] OR [Subject and Keywords = Psychologii zwierząt \- historia] OR [Subject and Keywords = Psychologia zwierząt \- podstawowe pojęcia] OR [Subject and Keywords = Psychopatologia porównawcza] OR [Title = Tierpsychologie] OR [Creator = Sommer, Robert \(1864–1937\)]