6De Raad, B.2000.Differential Psychology Encyclopedia of Psychology[C].Oxford: American Psychological Association an OUP.
7Domyei,Zolta n.2005.The Psychology of the Language Learner: Individual Differences in Second Language Acquisition[-M].London:Lawrence Erlbaum Associates Inc.
8Eysenck, M.W. 1994.Individual differences: Normal and Abnormal [M].Hove: Lawrence Erlbaum Associates.
9Larsen-Freeman, D.& M.Long. 1991.An Introduction to Second Language Acquisition Research[M].Essex: Longman Group.
10Selinker, L. 1972 .Interlanguage [J].Intemational Review of Applied Linguistics, (3).
