Every, Barbara. “‘Hedging’ in Scientific Writing.” Biomedical Editor. http://www.biomedicaleditor.com/
hedging.html#ixzz29V02GdKM.
Fogarty, Mignon. “Subjunctive Verbs.” Grammar Girl, March 5, 2009. http://grammar.quickanddirtytips.com/
subjunctive-verbs-was-i-were.aspx.
“Irregular Verb List.” EnglishClub.com. http://www.englishclub.com/vocabulary/irregular-verbs-list.htm.
King, Stephen. On Writing: A Memoir of the Craft. New York: Pocket Books, 2000.
Kipling, Rudyard. The Jungle Book. Project Gutenberg. 2012. http://www.gutenberg.org/files/236/236-h/236-h.htm.
LaRocque, Paula. The Book on Writing: The Ultimate Guide to Writing Well. Oak Park, IL: Marion Street Press, Inc., 2003.
O’Conner, Patricia T. Words Fail Me: What Everyone Who Writes Should Know About Writing. New York: Harcourt, Brace & Company, 1999.
“Perfect Tenses.” EnglishPlus.com. http://englishplus.com/grammar/00000361.htm.
Simmons, Robin L. “Auxiliary Verbs.” Grammar Bytes. http://www.chompchomp.com/terms/auxiliaryverb.htm.
“The Verb Tenses in English.” English Grammar Guide.
https://sites.google.com/site/englishgrammarguide/Home/the-verb-tenses-in-english.
Whitman, Neal. “‘Pet’ or ‘Petted’? ‘Grit’ or ‘Gritted’?” Grammar Girl, Aug 2, 2012.
http://grammar.quickanddirtytips.com/pet-or-petted.aspx.