Tontz, R. L. (1966). Foreign agricultural trade: Selected readings. Iowa State University Press.
Chicago-viite (17. p.)Tontz, Robert L. Foreign Agricultural Trade: Selected Readings. Ames: Iowa State University Press, 1966.
MLA-viite (8. p.)Tontz, Robert L. Foreign Agricultural Trade: Selected Readings. Iowa State University Press, 1966.
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