@book{150806,
	author = {Layzer, Judith A. and ebrary, Inc.},
	title = {Natural experiments},
	publisher = {MIT Press,},
	year = {c2008.},
	series = {American and comparative environmental policy},
	address = {Cambridge, Mass. :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10240754}
}