1. On Adolescence;Blos,1962
2. Use of play in psychodynamic psychotherapy;Coppolillo,2002
3. Animal Play Behavior;Fagan,1981
4. Ghosts in the nursery;Fraiberg;J Am Acad Child Psychiatry,1975
5. The concept of developmental lines. Normality and Pathology in Childhood;Freud,1965