Não informado. (1961). Agricultural Economic Report. U.S. Department of Agriculture, Economics, Statistics and Cooperative Service.
Chicago-viite (17. p.)Não informado. Agricultural Economic Report. Washington: U.S. Department of Agriculture, Economics, Statistics and Cooperative Service, 1961.
MLA-viite (8. p.)Não informado. Agricultural Economic Report. U.S. Department of Agriculture, Economics, Statistics and Cooperative Service, 1961.
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