Brown, J. D. (1988). Understanding research in Second Language Learning (2th edition). Cambridge: Cambridge University Press.
Falahati, R. (2006). The use of hedging across different disciplines and rhetorical sections of research articles. (papers from the 22th Northwest Linguistics Conference).
Farrokhi, F., &Emami, S. (2008). Hedges and Boosters in Academic Writing: Native vs. Non-native Research Articles in Applied Linguistics and Engineering. The Journal of Applied Linguistics, 1(2), 62-98.
Holmes, J. (1982). Expressing doubt and certainty in English.RELC Journal, 13(2), 19-28.
Hyland, K. (1996a). talking to academy: Forms of hedging in science research articles. Written Communication, 13(2), 251-281.
Hyland, K. (1996b). writing without conviction? Hedging in science research articles.Applied Linguistics, 17(14), 433-454.
Hyland, K. (1998). Boosting, hedging and the negotiation of academic knowledge.TEXT, 18(3), 349-382.
Hyland, K. (2000). Hedges, boosters and lexical invisibility: Noticing Modifiers in academic texts. Language Awareness, 9(4), 179-194.
Hyland, K., & Milton, J. (1997), qualification and certainty in L1 and L2 students’ writing.Journal of Second Language Writing, 6(2), 183-205.
Modirkhamene, S. (2006).The reading achievement of third language versus second language learners of English in relation to the Interdependence Hypothesis.International Journal ofMultilingualism, 13(4), 280-295.
Simin, S. and Tavangar, M. (2009).Metadiscourse knowledge and use in Iranian EFL writing. Asian EFL Journal, 11, 230-255.
Shengming, Y. (2009). The pragmatic development of hedging in EFL learners.Phd dissertation.Department of English, City University of Hong Kong.
Thompson, G. (2001). Interaction in academic writing: Learning to argue with the reader. Journal of Applied Linguistics, 22 (1), 58–77.
Varttala, T. (2001).Hedging on scientifically oriented discourse: exploring Variation according to Discipline and intended audience.
Electronic doctoral dissertation.Acta Electronica Universities Tamperensis 138, Received from http://acta.uta.fi/pdf/951-44-5195-3.pdf
Weigle, S. C. (2002). Assessing Writing. Cambridge: Cambridge University Press
Wishnoff, J., R. (2000) Hedging Your Bets: EFL Learners’ Acquisition of Pragmatic Devices in Academic Writing and Computer-mediated Discourse, Second Language Studies, no. 19.1.