@book{80,
	author = {Hoffmann, Laurence D. and Bradley, Gerald L},
	title = {Cálculo Aplicado a Administración, Economía, Contaduría y Ciencias Sociales /},
	publisher = {McGraw-Hill,},
	year = {1995.},
	address = {Bogotá :},
	edition = {5.}
}