United States. Department of Agriculture, United States. Foreign Agricultural Service, & Economic Research Service. The World agricultural situation. [s.n.
Cita Chicago (17th ed.)United States. Department of Agriculture, United States. Foreign Agricultural Service, i Economic Research Service. The World Agricultural Situation. Washington: [s.n.
Cita MLA (9th ed.)United States. Department of Agriculture, et al. The World Agricultural Situation. [s.n.
Atenció: Aquestes cites poden no estar 100% correctes.