@book{57738,
	author = {Angrist, Joshua David. and Pischke, Jörn-Steffen.},
	title = {Mostly harmless econometrics :},
	publisher = {Princeton University Press,},
	year = {c2009.},
	address = {Princeton :},
	url = {http://www.loc.gov/catdir/toc/ecip0823/2008027917.html}
}