@book{30621,
	author = {Dawsen, Christopher J. and ebrary, Inc.},
	title = {Geographic information systems},
	publisher = {Nova Science Publishers,},
	year = {2011.},
	series = {Environmental science, engineering and technology},
	address = {New York :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10686256}
}