Não informado. (1941). Crop Production. Department of Agriculture, Statistical Reporting Service.
Chicago-viite (17. p.)Não informado. Crop Production. Washington: Department of Agriculture, Statistical Reporting Service, 1941.
MLA-viite (8. p.)Não informado. Crop Production. Department of Agriculture, Statistical Reporting Service, 1941.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.