TY - BOOK A1 - Tinbergen, Niko T1 - Social behaviour in animals, Frome and London (Butler & Tanner) 1969. Y1 - 1969 ER - TY - JOUR A1 - Tinbergen, Niko T1 - Ethologie JF - G. Roth (Ed.), Kritik der Verhaltensforschung, München (Verlag C. H. Beck) 1974, pp. 118-155. Y1 - 1974 N1 - Marks in the copy ER -