@book{144942,
	author = {Helbig, Herbert.},
	title = {Gesellschaft und Wirtschaft der Mark Brandenburg im Mittelalter /},
	publisher = {de Gruyter,},
	year = {1973.},
	series = {Ver�offentlichungen der Historischen Kommission zu Berlin ;},
	address = {Berlin ;},
	note = {Includes index.},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10802076}
}