Não informado. (2001). Yearbook. American Public Health Association.
Chicago-referens (17:e uppl.)Não informado. Yearbook. New York: American Public Health Association, 2001.
MLA-referens (8:e uppl.)Não informado. Yearbook. American Public Health Association, 2001.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.