@book{76450,
	author = {Vermeer, Hans J. and ebrary, Inc.},
	title = {Luhmann's "social systems" theory},
	publisher = {Frank & Timme,},
	year = {c2006.},
	address = {Berlin :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10655477}
}