@book{208356,
	author = {Weinstein, Tilla, and ebrary, Inc.},
	title = {An introduction to Lorentz surfaces},
	publisher = {Walter de Gruyter,},
	year = {1996.},
	address = {Berlin ;},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10588555}
}