@book{52606,
	author = {Levy, Paul S. and Lemeshow, Stanley.},
	title = {Sampling of populations :},
	publisher = {Wiley,},
	year = {c2008.},
	series = {Wiley series in survey methodology},
	address = {Hoboken, N.J. :},
	edition = {4th ed.},
	url = {http://www.loc.gov/catdir/toc/ecip0810/2008004934.html}
}