1. Conditional reflex studies in mental retardation: A review;Astrup;American Journal of Mental Deficiency,1967
2. Motivational determinants of risk taking behavior;Atkinson;Psychological Review,1957
3. Personality development in retarded persons.;Balla,1979
4. Problems in comparative studies of mental retardates and normals;Baumeister;American Journal of Mental Deficiency,1967
5. Classroom interaction: Two studies of severely educationally subnormal children;Beveridge;Research in Education,1978