@unpublished{publication-5839,
	author={Fischbacher, Urs},
	institution={University of Zurich},
	issn={1424-0459},
	number={No. 21},
	series={Working paper series / Institute for Empirical Research in Economics},
	title={z-Tree - Zurich Toolbox for Readymade Economic Experiments - Experimenter's Manual},
	year=1999,
}