@book{121579,
	author = {Fogel, Robert William. and Engerman, Stanley L.},
	title = {Tiempo en la cruz : la economía esclavista en los Estados Unidos},
	publisher = {Siglo Ventiuno},
	year = {1981.},
	address = {México},
	note = {Reprint. Originally published: Boston, Mass. : Little, Brown, c1974.}
}