United States. Department of Agriculture. Economic Research Service. (1994). Agricultural resources and environmental indicators. The Service.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)United States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. Washington, DC: The Service, 1994.
توثيق جمعية اللغة المعاصرة MLA (الإصدار التاسع)United States. Department of Agriculture. Economic Research Service. Agricultural Resources and Environmental Indicators. The Service, 1994.