1. Breeding behaviour of the long-tailed skua Stercorarius longicaudus (Vieillot);Andersson;Ornis Scandinavicaa,1971
2. Vocalization in chicks and the concept of ‘stimulus contrast’;Andrew;Anim. Behav,1964
3. The ethological concept ‘releasing mechanism’ illustrated by a study of the stimuli eliciting egg-retrieving in the herring gull;Baerends;Anat. Rec,1957
4. The value of the concept ‘releasing mechanism’;Baerends,1959
5. La reconnaissance de l'oeuf par le Goéland argenté;Baerends;Bull. Soc. scient. Bretagne,1962