United Nations. Department of International Economic and Social Affairs. (1991). The sex and age distributions of population (1990 revision-.). United Nations.
Citazione stile Chigago Style (17a edizione)United Nations. Department of International Economic and Social Affairs. The Sex and Age Distributions of Population. 1990 revision-. New York: United Nations, 1991.
Citatione MLA (9a ed.)United Nations. Department of International Economic and Social Affairs. The Sex and Age Distributions of Population. 1990 revision-. United Nations, 1991.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.