@book{78967,
	author = {Sobel, Max A. and Lerner, Norbert.},
	title = {Precálculo},
	publisher = {Prentice-Hall,},
	year = {1998.},
	address = {Naucalpan, Méx. :},
	note = {Trad. de : Precalculus mathematics 5 ed. de 1995.}
}