"invective." Collins Essential English Dictionary, 2004, 2006. HarperCollins Publishers.
"invective." WordNet 3.0, Farlex clipart collection.(sic) 2003-2008. Princeton University, Clipart.com, Farlex Inc. 13 May 2017 http://www.thefreedictionary.com/invective. Note: This MLA format citation (which provided the most information regarding this unusual citation) was provided on the web page.