@book{19270,
	author = {Obregón, Eduardo.},
	title = {Las clases sociales; qué son y qué significan.},
	publisher = {Zero},
	year = {1970, c1964.},
	series = {Colección Lee y Discute. Serie Roja,no.3},
	address = {Madrid},
	edition = {3 ed.}
}