@unpublished{publication-5365,
	author={Fehr, Ernst and Hart, Oliver and Zehnder, Christian},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 393},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={Contracts as Reference Points Experimental Evidence},
	year=2008,
}