Não informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Natural Resources & Energy. New York: United Nations, Department of Technical Cooperation for Development.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Natural Resources & Energy. United Nations, Department of Technical Cooperation for Development.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.