United Nations Department of International Economic and Social Affairs. (1991). Concise report on the world population situation in 1991, with a special emphasis on age structure. United Nations.
শিকাগো স্টাইল (17 তম সংস্করণ) উদ্ধৃতিUnited Nations Department of International Economic and Social Affairs. Concise Report on the World Population Situation in 1991, with a Special Emphasis on Age Structure. New York: United Nations, 1991.
M.L.A (9 ম সংস্করণ) উদ্ধৃতিUnited Nations Department of International Economic and Social Affairs. Concise Report on the World Population Situation in 1991, with a Special Emphasis on Age Structure. United Nations, 1991.
সতর্কবাণী: সাইটেশন সবসময় 100% নির্ভুল হতে পারে না.