@book{76668,
	author = {Dagum, Camilo and Bee de Dagum, Estela M.},
	title = {Introducción a la econometría  },
	publisher = {Siglo Veintiuno Editores,},
	year = {1980},
	series = {Economía y demografía},
	address = {México :},
	edition = {7a ed.}
}