@book{4497,
	author = {Williamson, John B. and Pampel, Fred C. and ebrary, Inc.},
	title = {Old-age security in comparative perspective},
	publisher = {Oxford University Press,},
	year = {c1993.},
	address = {New York :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10279453}
}