@book{2053,
	author = {Ferrari, Francisco de and Etala, Juan José  },
	title = {Los principios de la seguridad social / },
	publisher = {Depalma,},
	year = {1972.},
	address = {Buenos Aires :},
	edition = {2a. ed. act.},
	note = {Notas y citas a pie de página.}
}