Não informado. (1961). Agricultural Economic Report. U.S. Department of Agriculture, Economics, Statistics and Cooperative Service.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Agricultural Economic Report. Washington: U.S. Department of Agriculture, Economics, Statistics and Cooperative Service, 1961.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Agricultural Economic Report. U.S. Department of Agriculture, Economics, Statistics and Cooperative Service, 1961.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.