6Burns,L.C.Vagueness:an investigation into natural languages and the Sorite Paradox[M].Netherlands:Kluwer Academic Publlishers,1991.Lakoff,G.Hedges:A study in meaning criteria and the logic of fuzzy concepts[A].In P.Peranteau,J.Levi and G.Phares (eds.)[C].1972.Levinson,S.C.Pragmatics[M].Cambridge:CUP,1983.
7John Isaceed.Semantics[M].北京:外语教学与研究出版社,2000.
8Verschueren J.Understanding Pragmatics[M].London and New York:Arnold,1999.
9Williamson,T.Vagueness[M].London and New York:Routledge,1994.
