3Krashen, S. Formal and Informal Linguistic Environments in Language Acquisitlon and Language Learning [J]. TESOL Quarterly. Vol. 10, No.2,1976:157-168.
4Stem, H. H. Fundamental Concepts of Langunge Teaching [M]. Oxford: OUP, 1983.
5Corder, S. P. Introducing Applied Linguistics [M]. Harmondsworth: Penguin, 1973.
6Krashen, S. Principles and Practice in Second Language Acquisition [M]. Oxford: Pergamon, 1982.
7Howatt, A.P.R. A History of English Language Teaching [ M ]. Oxford:Oxford University Press, 1984.
8Odlin, Terence. Language Transfer : Cross-Linguistic Influence in Language Learning[M]. Crambridge: Cambridge University Press, 1989.
9Brown, H.Douglas. Principles of Language Learning and Teaching [M].New Jersey: Prentice Hall, 1994.
10Krashen, Stephen D. The Input Hypothesis: Issues and Implications [M].London: Longman, 1985.
