00297nam a2200097Ia 4500008004100000082001800041100002400059245005400083264005200137300001000189200526s9999||||xx |||||||||||||| ||und||  a616.855 4 PER  aPerkins, William H. 0aWhite House Conference on Mental Retardation 1963  bU.S. Department of Health Education and Welfare  a153p.