1. 1. Mahler MS Pine F Bergman A: The Psychological Birth of the Human Infant. New York Basic Books Inc 1975 p 72.
2. 2. Piaget J Inhelder B: The Psychology of the Child. New York Basic Books Inc 1969.
3. 3. Modell A: Object Love and Reality. New York International Universities Press 1968.
4. 4. Lewis M: Clinical Aspects of Child Development. Philadelphia Lea & Febiger 1973.
5. 5. Winnicott DM: The Maternal Process and The Facilitating Environment. New York International Universities Press 1968.