@book{27140,
	author = {Keedy, Mervin L. and Bittinger, Marvin L.},
	title = {Algebra y trigonometría},
	publisher = {Fondo Educativo Interamericano,},
	year = {1981},
	address = {Bogotá :},
	note = {Trad. de la 2 ed. en inglés de 1978}
}