1. An introduction to the study of the ethology of cichlid fishes;Baerends;Behaviour,1950
2. Beiträge zur Biologie, namentlich Ethologie and Psychologie der Anatiden;Heinroth;Int. Ornithol. Congress, Berlin,1910
3. An analysis of the parental behaviour of the male three-spined stickleback (Gasterosteus aculeatus L.);Iersel;Behaviour,1953
4. Vergleichende Bewegungsstudien an Anatiden;Lorenz;J. Ornithol., Erg. Bd.,1941