Web Sources
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"Genghis Khan & The Battle of Ain Jalut." BEYONDbones. N.p., n.d. Web. 23 May 2014. <http://blog.hmns.org/2009/02/genghis-khan-the-battle-of-ain-jalut/>.
"Main Page." Wikipedia. Wikimedia Foundation, 20 May 2014. Web. 20 May 2014. <http://en.wikipedia.org/wiki/Main_Page>.
"Trebuchet Physics." Real World Physics Problems. N.p., n.d. Web. 20 May 2014. <http://www.real-world-physics-problems.com/trebuchet-physics.html>.