@book{420,
	author = {Kagan, Neil.},
	title = {National Geographic concise history of the world :},
	publisher = {National Geographic Society,},
	year = {c2006.},
	address = {Washington, D.C. :},
	url = {http://www.loc.gov/catdir/enhancements/fy0643/2005052248-b.html}
}