Northrup, H. R. (1968). The Negro in the aerospace industry. Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press.
Dyfyniad Arddull ChicagoNorthrup, Herbert R. The Negro in the Aerospace Industry. Philadelphia: Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press, 1968.
Dyfyniad MLANorthrup, Herbert R. The Negro in the Aerospace Industry. Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press, 1968.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.