3Beebe S A, Masterson J T. Communicating in small groups. New York: Longman,2000.
4Johnson D W, Roger T S. Positive Interde pendence: Key to effective cooperation. In Hertz-Lazarowitz, R. & Miller[M]. N. (Eds.), Interaction in cooperative groups. 1995.
5Stevens R J. Cooperative learning and classroom structure[J]. Teaching and teacher education, 2005 (02).
