@unpublished{publication-5152,
	author={Fehr, Ernst and Hart, Olive and Zehnder, Christian},
	institution={University of Zurich},
	issn={1664-7041},
	number={No. 43},
	pages=54,
	series={Working paper series / Department of Economics},
	title={How do informal agreements and renegotiation shape contractual reference points?},
	year=2011,
}