5Schiffrin, Debroah. Discourse Markers [M]. New York:Cambridge University Press, 1987.
6Watts, Richard. Taking the pitcher to the "well”: Nativespeakers, perception of their use of discourse markers inconversation [J]. Journal of Pragmatics 13: 203-237, 1989.
7Altenberg, B. & Tapper, M. The use of adverbial connectors in advanced Swedish learners' written English[A].Granger, S.(ed.) Learner English on Computer[C]. London: Longman, 1998.
8Briton, L. J. Pragmatic Markers in English: Grammatication and Discourse Functions[M]. New York: Moutonde Gruyter, 1996.
9Chaudreon, C. & Richards, J. C. The effects of discourse markers on the comprehension of lectures[J]. Applied Linguistics, 1986, (7).
10Flowerdew, J. & Tauroz, S. The effects of discourse markers on second language lecture comprehension[J].SSLA, 1995, (17).