@book{4449,
	author = {Crilly, Tony and Herrando Pérez, Enrique},
	title = {50 cosas que hay que saber sobre matemáticas},
	publisher = {Ediciones Ariel},
	year = {2011},
	address = {Barcelona :},
	url = {https://www.biblioeco.unsa.edu.ar/pmb/images/libros/L127653.jpg}
}