5ELLIS R.Understanding second language acquisition[M].Oxford Univ.Press,1985:127-248.
6ELLIS R.The study of second language acquisition[M].Oxford Univ.Press,1994:101-123.
7HAWKINS R.Second language syntax:a generative introduction[M].Blackwell,2001:58-122.
8KRASHEN SD.Principles and practice in second language acquisition[M].New York:Pergamon Press Ltd,1982:47-131.
9LARSEN-FREEMAN D,LONG M.An introduction to second language acquisition and research[M].London:Longman,1991:43-82.
10LONG M.Instructed interlanguage development[A].In L.M.Beebe,(ed.) Issues in Second Language Acquisition:Multiple Perspectives[C].New York:Newbury House Publishers,1988:60.
