@book{6521,
	author = {Pacheco, José Emilio, },
	title = {La edad de las tinieblas :},
	publisher = {El Colegio Nacional, },
	year = {c2009},
	address = {México, D.F. :},
	url = {https://www.cicy.mx/sitios/sib/doctoelectronico/7186.pdf}
}