6[1]Brown, H. D. Principle of Language Learning and Teaching [ M]. New Jersey: Prentice Hall, 1987.
7[2]Selinker, L. Interlanguage[J]. IRAL, 1972,(10).
8[3]Ellis, Rod. The Study of Second Language Acquisition[M].Oxford University Press, 1994.
9[4]Lenneberg, E. Biological Foundations of Language [M].New York: Wiley & Sons,1967.
10[5]Lamendella,T. General Principles of Neurofunctional Organization of Their Manifestations in Primary & Non-primary Language Acquisition [ J ]. Language Learning, 1977,(27).