@book{137228,
	author = {Schaie, K. Warner and ebrary, Inc.},
	title = {Social structures},
	publisher = {Springer,},
	year = {c2007.},
	series = {Societal impact on aging series},
	address = {New York :},
	url = {http://site.ebrary.com/lib/strathmore/Doc?id=10176165}
}