Não informado. (1931). Dairy situation. U.S. Department of Agriculture, Economic Research Service.
Chicago-Zitierstil (17. Ausg.)Não informado. Dairy Situation. Washington: U.S. Department of Agriculture, Economic Research Service, 1931.
MLA-Zitierstil (8. Ausg.)Não informado. Dairy Situation. U.S. Department of Agriculture, Economic Research Service, 1931.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.