@book{60892,
	author = {Strogatz, Steven H. and Joffray, Don, and ebrary, Inc.},
	title = {The calculus of friendship},
	publisher = {Princeton University Press,},
	year = {c2009.},
	address = {Princeton :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10320504}
}