@book{85478,
	author = {ZILL, Dennis G and Cullen, Michael R., coaut.Ì},
	title = {Ecuaciones Difernciales : con valor en la frontera },
	publisher = {: Cengage Learning},
	year = {2009},
	address = {México },
	edition = {7a ed},
	note = {Incluye índice}
}