@book{22803,
	author = {Shryock, Henry S. and Siegel, Jacob S.},
	title = {The methods and materials of demography /},
	publisher = {Academic Press,},
	year = {c1976.},
	address = {New York :},
	edition = {Condensed ed. },
	url = {http://www.loc.gov/catdir/description/els031/76018312.html}
}