@book{7485,
	author = {Henrich, Natalie, and Henrich, Joseph Patrick. and ebrary, Inc.},
	title = {Why humans cooperate},
	publisher = {Oxford University Press,},
	year = {2007.},
	series = {Evolution and cognition},
	address = {Oxford ;},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10271627}
}