Não informado. (1987). Education and Training in Mental Retardation and Developmental Disabilities. Council for Exceptional Children, Division on Mental Retardation.
Chicago-referens (17:e uppl.)Não informado. Education and Training in Mental Retardation and Developmental Disabilities. Reston, Va: Council for Exceptional Children, Division on Mental Retardation, 1987.
MLA-referens (8:e uppl.)Não informado. Education and Training in Mental Retardation and Developmental Disabilities. Council for Exceptional Children, Division on Mental Retardation, 1987.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.