00473nam a2200097Ia 4500008004100000082001700041100003300058245025800091264001700349300000900366200527s9999||||xx |||||||||||||| ||und||  a371.92 CLA L  aClarke, A.D.B. , Lewis, M.M. 0aLearning Speech and Thought in the Mentally Retarded: Proceedings of Symposia 4 and 5 Held at the Middlesex Hospital Medical Sessions on 31st Oct1969 and 20th March 1970, Under the Auspices of the Institute for Research in the Mental Retardation, London  bLondonc1972  a83p.