Não informado. (1971). Nation's Health. American Public Health Association.
Chicago-referens (17:e uppl.)Não informado. Nation's Health. New York: American Public Health Association, 1971.
MLA-referens (8:e uppl.)Não informado. Nation's Health. American Public Health Association, 1971.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.