@book{89444,
	author = {Yescas Vásquez, César.},
	title = {Zonificación agroclimática de la Sierra Norte de Oaxaca /},
	publisher = {El autor,},
	year = {2004.},
	address = {Chapingo, Méx. :},
	url = {http://10.13.5.2/tesis/100972.pdf}
}