@book{2020,
	author = {Stewart, James and Redlin, Lothar},
	title = {Precálculo: Matemáticas para el cálculo},
	publisher = {Cengage Learning,},
	year = {2017},
	address = {México :},
	edition = {7 ed.},
	url = {https://itmsp.museknowledge.com/UOH?qurl=https://libros-uoh.uoh.cl/ESCUELADEEDUCACION/PEDAGOGIAMATEMATICA/Precalculo//}
}