1. Children as teachers: Theory and research on tutoring;Allen,1976
2. Learning thorugh tutoring: Low-achieving children as tutors;Allen;Journal of Experimental Educvation,1974
3. Interaction process analysis: A method for the study of small groups;Bales,1950
4. Thinking: An experimental and social study;Bartlett,1958
5. Social ecology and ethology of mental retardation.;Berkson,1978