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Encyclopædia Britannica. Photograph. Encyclopædia Britannica. Web. 6 Nov. 2013. <http://school.eb.com/levels/high/article/32600/media?assemblyId=97337>.
Shinfani, Stacey. No Words Used to Start with X. Digital image. Flickr. 15 Apr. 2008. Web. 23 Sept. 2015. <http://bit.ly/1KuHMNZ>.
A Dictionary of the English Language: A Digital Edition of the 1755 Classic by Samuel Johnson. Edited by Brandi Besalke. Last modified: November 25, 2013. http://johnsonsdictionaryonline.com/.