http://en.wikipedia.org/wiki/Ides_of_March http://ancienthistory.about.com/od/caesar1/g/idesofmarch.htm http://penelope.uchicago.edu/~grout/encyclopaedia_romana/calendar/ides.html http://news.nationalgeographic.com/news/2004/03/0311_040311_idesmarch.html http://news.nationalgeographic.com/news/2009/03/090313-ides-of-march-facts.html