@book{227883,
	author = {Wooldridge, Jeffrey M., and ebrary, Inc.},
	title = {Econometric analysis of cross section and panel data},
	publisher = {MIT Press,},
	year = {c2010.},
	address = {Cambridge, Mass. :},
	edition = {2nd ed.},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10453042}
}