@book{50573,
	author = {Plan Zacapoaxtla. México and ENA. Colegio de Postgraduados. Chapingo, Méx.},
	title = {Informe anual, 19 -.},
	publisher = {ENA. Colegio de Postgraduados,},
	year = {19 -.},
	address = {Chapingo, Méx. :},
	note = {La biblioteca tiene: 1974-75, 1975-76, 1976-77}
}