@book{51497,
	author = {Singleton, Royce.},
	title = {Approaches to social research /},
	publisher = {Oxford University Press,},
	year = {1988.},
	address = {New York :},
	note = {Includes indexes.},
	url = {http://www.loc.gov/catdir/enhancements/fy0636/87012187-d.html}
}