1. The age of onset of ambivalence in early infancy: Indications from the study of laughing;Ambrose;Journal of Child Psychology and Psychiatry,1963
2. Criteria for use in describing facial expressions of children;Blurton Jones;Human Biology,1971
3. Categories of child-child interaction;Blurton Jones,1972
4. Characteristics of ethological studies of human behavior;Blurton Jones,1972