@book{22571,
	author = {Tignor, Robert L.},
	title = {Worlds together, worlds apart :},
	publisher = {W.W. Norton,},
	year = {c2008.},
	address = {New York :},
	edition = {2nd ed.},
	url = {http://www.loc.gov/catdir/toc/ecip0813/2008012276.html}
}