Bekalu, M. A. (2006) Presupposition in news discourse. Discourse & Society, 17(2), 147–172. https://doi.org/10.1177/0957926506060248
 
 Biber, D.; Johansson, S.; Leech, G.; Conrad, S. and Finegan, E. (1999) Longman Grammar of Spoken and Written English. London: Longman.
 
He, Z. R. (2003) Notes on Pragmatics. Nanjing: Nanjing Normal University Press. 
 
Huang, Y. (2007) Pragmatics. Oxford: Oxford University Press. 
 
Levinson, Stephen, C. (1983) Pragmatics. Cambridge: Cambridge University Press.
 
Liang,  R.,  &  Liu,  Y.  (2016) An Analysis of Presupposition Triggers in Hilary Clinton‘s First Campaign Speech. International Journal of English Linguistics, 6(5), 68–73. 
https://www.researchgate.net/publication/331351509_PRESUPPOSITION_TRIGGERS_IN_THE_WASHINGTON_POST_AND_LOST_ANGELES_TIMES_ONLINE_NEWS [accessed Jul 01 2020].
 
Richardson, John E. (2007) Analyzing Newspapers: An approach from critical discourse analysis. NY: Palgrave, Macmillan.
Yule, G. (1996) Pragmatics. Oxford: Oxford University Press.
Zare,  J.,  Abbaspour,  E.,  and  Nia,  Mahji  R.  (2012) Presupposition  Trigger  –A Comparative Analysis of Broadcast News Discourse, An International Journal of Linguistics, (4)3, pp 734 -743.   http://dx.doi.org/10.5296/ijl.v4i3.2002
 
Appendix
4-      https://www.bbc.com/news/world-asia 52791870?intlink_from_url=https://www.bbc.com/news/world/asia&link_location=live-reporting-story [accessed March 25 2020]
5-      https://www.bbc.com/news/world-middle-east-52034646[accessed March 25 2020]
6-      https://www.bbc.com/news/world-middle-east-5186873[accessed March 25 2020]