Robertson, D. (1972). Internation trade policy. London: Mamillan.
Trích dẫn kiểu ChicagoRobertson, David. Internation Trade Policy. London: Mamillan, 1972.
MLA引文Robertson, David. Internation Trade Policy. London: Mamillan, 1972.
警告：这些引文格式不一定是100％准确.