Não informado. (1957). Foreign agriculture circular. U.S. Department of Agriculture, Foreign Agricultural Service.
Chicago-viite (17. p.)Não informado. Foreign Agriculture Circular. Washington: U.S. Department of Agriculture, Foreign Agricultural Service, 1957.
MLA-viite (8. p.)Não informado. Foreign Agriculture Circular. U.S. Department of Agriculture, Foreign Agricultural Service, 1957.
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