Tontz, R. L. (1966). Foreign agricultural trade: Selected readings ([1st ed.].). Iowa State University Press.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিTontz, Robert L. Foreign Agricultural Trade: Selected Readings. [1st ed.]. Ames: Iowa State University Press, 1966.
M.L.A (9 ম সংস্করণ) উদ্ধৃতিTontz, Robert L. Foreign Agricultural Trade: Selected Readings. [1st ed.]. Iowa State University Press, 1966.