Não informado. (1976). Important for the Future. United Nations, Institute for Training and Research.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিNão informado. Important for the Future. New York: United Nations, Institute for Training and Research, 1976.
M.L.A (8 ম সংস্করণ) উদ্ধৃতিNão informado. Important for the Future. United Nations, Institute for Training and Research, 1976.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.