@unpublished{publication-5490,
	author={Frey, Bruno S and Osterloh, Margit},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 302},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Evaluations: Hidden Costs, Questionable Benefits, and Superior Alternatives},
	year=2006,
}