Oshima, Alice, and Ann Hogue, Introduction to Academic Writing. 3rd ed. Harlow: Pearson Education ESL, 2005.
Quirk, Randolph, Greenbaum, Sidney, Leech, Geoffrey, and Jan Svartvik, A Comprehensive Grammar of the English Language. New York: Longman Inc., 1985.
The Writing Centre at the University of Wisconsin – Madison, The Writer’s Handbook – Using Transitions. [Accessed at http://writing.wisc.edu/Handbook/Transitions.html on 20 January 2017.]