[1]Austin,John.L.How to Do Things With Words[M].Oxford:Oxford University Press.1962.
[2]Bnmffit,C.J.&Johnson,K.The Communicative Aporoach to Language Teaching[M].Oxford:OUP,1979.
[3]Halliday.M.A.K.Language as Social Semiotic:The Social Interpretation of Language and Meaning[M].London:Edward hrnold.1978.
[4]HaUiday,M.A.K.and R.Hasan.Cohesion in English[M].London:Longman.1976.