@book{283880,
	author = {Landsburg, Steven E.,},
	title = {More sex is safer sex :},
	publisher = {Free Press,},
	year = {2007.},
	address = {New York :},
	note = {Includes appendix and index.},
	url = {http://www.loc.gov/catdir/enhancements/fy0701/2006050846-d.html}
}