Bureau of Education for the Handicapped Commitment and Program in Early Childhood Education

Hunt J. M. Intelligence and experience. New York: Ronald Press, 1961.

Kirk S. A. Early education of the mentally retarded. Urbana, Ill.: University of Illinois Press, 1958.

Martin E. W. A new outlook for education of handicapped children. American Education, 1970, 6 (3), 7–10.

Piaget J. The early growth of logic in the child. New York: W. W. Norton & Co., 1969.

Skeels H. M. Adult status of children with contrasting early life experiences. Monographs of the Society for Research in Child Development, 1966, 31 (3), 1–65.