1. Bailer, I. (1970). Emotional disturbances and mental retardation: Etiological and conceptual relationships. InPsychiatric approaches to mental retardation. F. Menolascino, Ed. Basic Books, N.Y.
2. Chess, (1970). Emotional Problems in Mentally Retarded Children, InPsychiatric Approaches to Mental Retardation. F. Menolascino, Ed. Basic Books, N.Y.
3. Harter, S. (1968). Piaget's theory of intellectual development: The changing world of the child.Connecticut Medicine 32, 444?456.
4. Hayes, M. (1977). The responsiveness of mentally retarded children to psychotherapy. Smith College Studies in Social Work47, 112?153.
5. Henderson, P. B. (1982) In Jakab, I. (Ed.).Mental retardation. New York: Karger Continuing Education Series.