@book{48991,
	author = {De Vaus, David.},
	title = {Surveys in social research /},
	publisher = {Routledge, },
	year = {2002. },
	series = {Social research today},
	address = {London : },
	edition = {5th ed.},
	url = {http://www.columbia.edu/cgi-bin/cul/resolve?clio4241166}
}