@unpublished{publication-7599,
	author={Buchholz, Wolfgang and Falkinger, Josef and Ruebbelke, Dirk},
	institution={University of Zurich},
	number=566,
	pages=27,
	series={Working Paper Series in Economics and Econometrics},
	title={Non-governmental public norm enforcement in large societies as a two-stage game of voluntary public good provision},
	year=2011,
}