@book{774,
	author = {Walker, B. H., },
	title = {Management of semi-arid ecosystems /},
	publisher = {Elsevier, },
	year = {1979},
	series = {Developments in agricultural and managed forest ecology ;},
	address = {Amsterdam ; New York :},
	url = {https://www.cicy.mx/sitios/sib/doctoelectronico/784.pdf}
}