@book{71488,
	author = {FAO and Spaargaren, O. C.},
	title = {World reference base for soil resources},
	publisher = {FAO,},
	year = {1998},
	series = {FAO. Informes sobre recursos mundiales de suelos},
	address = {Rome :},
	note = {c.2-4 no tienen serie y corresponden al año 1994.}
}