@book{216997,
	author = {Williams, George C. and ebrary, Inc.},
	title = {Natural selection},
	publisher = {Oxford University Press,},
	year = {1992.},
	series = {Oxford series in ecology and evolution ;},
	address = {New York :},
	url = {http://site.ebrary.com/lib/strathmore/Doc?id=10085355}
}