@unpublished{publication-5515,
	author={Kuhn, Andreas and Ruf, Oliver},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 277},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Einf{\"u}hrung in die Statistiksoftware STATA},
	year=2006,
}