Παραπομπή σε μορφή APA (7η εκδ.)

Northrup, H. R. (1969). The Negro in the rubber tire industry. Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press.

Παραπομπή σε μορφή Chicago (17η εκδ.)

Northrup, Herbert R. The Negro in the Rubber Tire Industry. Philadelphia: Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press, 1969.

Παραπομπή σε μορφή MLA (8th εκδ.)

Northrup, Herbert R. The Negro in the Rubber Tire Industry. Industrial Research Unit, Wharton School of Finance and Commerce, University of Pennsylvania; distributed by University of Pennsylvania Press, 1969.