@book{40024,
	author = {Galvis Hernández, Gustavo, and Martínez Zuleta, Claudia},
	title = {Servicios Públicos y Medio Ambiente .},
	publisher = {Universidad Externado de Colombia,},
	year = {2011.},
	address = {Bogotá D.C, Colombia :},
	edition = {1.},
	note = {Incluye Indice.}
}