@book{12663,
	author = {Leff, Enrique. and Naciones Unidas para el Medio Ambiente},
	title = {Saber ambiental :},
	publisher = {PNUMA :},
	year = {2002.},
	series = {Ambiente y democracia},
	address = {México :},
	edition = {3a ed. corregida y aumentada}
}