@book{6637,
	author = {Chang, Kang-Tsung.},
	title = {Introduction to Geographic Information Systems /},
	publisher = {McGraw-Hill,},
	year = {c2008.},
	address = {Boston :},
	edition = {4th ed.},
	url = {http://www.loc.gov/catdir/toc/ecip0617/2006023787.html}
}