Cita APA (7th ed.)

Travis, W. P. (1964). Theory of trade and proterction. Harvard Univ. pre.

Cita Chicago (17th ed.)

Travis, William Penfield. Theory of Trade and Proterction. Cambridge: Harvard Univ. pre, 1964.

Cita MLA (9th ed.)

Travis, William Penfield. Theory of Trade and Proterction. Harvard Univ. pre, 1964.