APA

United Nations (New York). Department of Economic and Social Affairs. Population Division, . (2001). World population prospects. New York: United Nations.

Chicago

United Nations (New York). Department of Economic and Social Affairs. Population Division, . 2001. World population prospects. New York: United Nations.

Harvard

United Nations (New York). Department of Economic and Social Affairs. Population Division, . (2001). World population prospects. New York: United Nations.

MLA

United Nations (New York). Department of Economic and Social Affairs. Population Division, . World population prospects. New York: United Nations. 2001.