Development and training of referential communication in children with mental retardation. Brownell MD, Whiteley JH. Am J Ment Retard. 1992 Sep;97(2):161-71. PMID: 1418931
[Secondary prevention of mental retardation]. Cravioto J. Gac Med Mex. 1971 Apr;101(4):457-64. PMID: 5104575
Mental retardation: who says what to whom. Goldberg II. Am J Ment Defic. 1966 Jul;71(1):4-12. PMID: 5964021
The importance of prevention in mental retardation. Dybwad G. Ment Retard. 1969 Apr;7(2):3-6. PMID: 5785038