@book{2850,
	author = {Burrough, P. A.},
	title = {Principles of geographical information systems for land resources assessment /},
	publisher = {Clarendon Press ;},
	year = {1986.},
	series = {Monographs on soil and resources survey ;},
	address = {Oxford [Oxfordshire] :},
	url = {http://www.loc.gov/catdir/enhancements/fy0639/85024661-d.html}
}