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.
Lua i Stíl Chicago (17ú heag.)United 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.
Lua MLA (9ú heag.)United 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.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.