@book{813,
	author = {Levy, Paul S. and Lemeshow, Stanley.},
	title = {Sampling of populations :},
	publisher = {Wiley,},
	year = {c1999.},
	address = {New York :},
	edition = {3rd ed.},
	note = {"Wiley-Interscience publication."},
	url = {http://www.loc.gov/catdir/bios/wiley042/98020498.html}
}