5S.D.Krashen.Second Language Acquisition and Second Language Learning[M].Oxford:Pergamon Press,1981.20~32.
6Stephen D. Krashen. The Input Hypothesis : Issues and Implication[M]. Longman Inc., New York,1985.
7Richard Kern and Mark, Warschauer. Chapter I Introduction: Theory and Practice of Network-Based Language Teaching in Network-based language teaching: Concepts and Practice: Cambridge University Press, 2000. http://www.lll.hawaii.edu/markw.