2Olsen, R & Kagan, S. About cooperative learning [M]. InC. Kessler(Ed.), Cooperative language learning A teacher' s resource book. Englewood Gliffs, NJ Prentice Hall, 1992.
3David Nunan. Collaborative Language Learning and Teaching[M]. Cambridge University Press. 1992:30.
10McGroarty,M..Cooperative learning and second language acquisition.In D.D.Holt (Ed.),Cooperative learning.Washington,DC:Center for Applied Linguistics & ERIC clearinghouse on Languages and Linguistics,1993.
