"Fractal." American Heritage® Dictionary of the English Language, Fifth Edition. 2011. Houghton Mifflin Harcourt Publishing Company 11 Mar. 2015 http://www.thefreedictionary.com/fractal
Hart, Vi. "Doodling in Math: Infinity Elephants." Khan Academy. N.p., n.d. Web. 09 Mar. 2015.
"Infinite Series." Math. N.p., n.d. Web. 08 Mar. 2015.
Krahula, Beckah. One Zentangle A Day. Beverly, MA: Quarry, 2012. Print.
Lodder, Jerry. "Proportionality in Similar Triangles." Mathematical Association of America. New Mexico State University, July 2010. Web. 11 Mar. 2015.
Parberry, Ian. "Straight Line Curves." Ian Parberry PhD. N.p., n.d. Web. 09 Mar. 2015.