Não informado. (2004). World population. U.S. Department of Commerce, Bureau of the Census.
Chicago-referens (17:e uppl.)Não informado. World Population. Washington: U.S. Department of Commerce, Bureau of the Census, 2004.
MLA-referens (8:e uppl.)Não informado. World Population. U.S. Department of Commerce, Bureau of the Census, 2004.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.