@book{52165,
	author = {Kohler, Ulrich. and Kreuter, Frauke.},
	title = {Data analysis using stata /},
	publisher = {Stata Press,},
	year = {c2005, 2012.},
	address = {College Station, Tex. :},
	edition = {3rd ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy1302/2012934051-b.html}
}