Não informado. (1931). Dairy situation. U.S. Department of Agriculture, Economic Research Service.
Chicago-viite (17. p.)Não informado. Dairy Situation. Washington: U.S. Department of Agriculture, Economic Research Service, 1931.
MLA-viite (8. p.)Não informado. Dairy Situation. U.S. Department of Agriculture, Economic Research Service, 1931.
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