United States. Department of Agriculture. Economic Research Service. (1994). Agricultural resources and environmental indicators. The Service.
Chicago Style (17th ed.) ZitazioaUnited States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. Washington, DC: The Service, 1994.
MLA (9th ed.) ZitazioaUnited States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. The Service, 1994.