1. The development of mother-infant attachment;Ainsworth,1973
2. The application of the idea of homology to behavior;Atz,1970
3. Locks and beagles;Beach;American Psychologist,1969
4. The development of social interaction, play, and metacom-munication in mammals: An ethological perspective;Bekoff;Quarterly Review of Biology,1972
5. The nature of the child's tie to his mother;Bowlby;International Journal of Psychoanalysis,1958