Não informado. (2002). Circular of the United States Naval Observatory. U.S. Naval Observatory.
Chicago-referens (17:e uppl.)Não informado. Circular of the United States Naval Observatory. Washington: U.S. Naval Observatory, 2002.
MLA-referens (8:e uppl.)Não informado. Circular of the United States Naval Observatory. U.S. Naval Observatory, 2002.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.