Travis, W. P. (1964). Theory of trade and proterction. Harvard Univ. pre.
Chicago Style (17. basım) AtıfTravis, William Penfield. Theory of Trade and Proterction. Cambridge: Harvard Univ. pre, 1964.
MLA (9th ed.) AtıfTravis, William Penfield. Theory of Trade and Proterction. Harvard Univ. pre, 1964.
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