1. Object relations, dependency and attachment: A theoretical review of the infant–mother relationship;Ainsworth;Child Development,1969
2. The development of the smiling response in early infancy;Ambrose,1961
3. Cognitive aspects of role taking in children;Feffer;J. Personal,1960
4. The Development of Role-Taking and Communication Skills in Children;Flavell,1968
5. Private speech: Four studies and a review of theories;Kohlberg;Child Development,1968