@book {Li2005CRCPress,
	title = {{Digital Terrain Modeling: Principles and Methodology}},
	year = {2005},
	pages = {319},
	publisher = {CRC Press},
	organization = {CRC Press},
	address = {Boca Raton, Florida},
	author = {Li, Z. and Zhu, Q. and Gold, C.}
}