@book{87831,
	author = {Martínez Bautista, Isaias.},
	title = {Caracterización del sistéma de cultivo milpa, en dos municipios de la sierra Mazateca alta, Oaxaca.},
	publisher = {El autor,},
	year = {2003.},
	address = {Chapingo, Méx. :},
	url = {http://10.13.5.2/tesis/99348.pdf}
}