@book{217490,
	author = {Bustillos Villalobos, José Filiberto and Ortíz Valdez, Marcial},
	title = {Determinación de horas frio en el Estado de Zacatecas /},
	publisher = {El autor,},
	year = {1989.},
	address = {Zacatecas, Zacatecas :},
	url = {http://10.13.5.2/tesis/tl/1968-3_Bustillos-Villalobos_Jose_Filiberto.pdf}
}