@unpublished{publication-5643,
	author={Frey, Bruno S and Stutzer, Alois},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 190},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Happiness Research: State and Prospects},
	year=2004,
}