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.
芝加哥风格引文Northrup, 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.
MLA引文Northrup, 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.
警告：这些引文格式不一定是100％准确.