1. Chickering AW, Gamson ZF: Applying the Seven Principles for Good Practice in Undergraduate Education: New Direction for Teaching and Learning No. 47. San Francisco, Jossey-Bass , 1991.
2.
2. Bonwell CC, Eison JA: Active learning: creating excitement in the classroom. ERIC Clearinghouse on Higher Education 1991(1);ED 340272.
3.
3. Cohen PA, Kulik JA, Kulik C-LC: Educational outcomes of peer tutoring: a meta analysis of finding . Amer Ed Research J1982;19(2): 237–248 .