APA (7e ed.) Bronvermelding

Pen, J. (1967). A primer on international trade. Random House.

Chicago (17e ed.) Bronvermelding

Pen, J. A Primer on International Trade. New York: Random House, 1967.

MLA (9e ed.) Bronvermelding

Pen, J. A Primer on International Trade. Random House, 1967.