Não informado. (1978). World Health Statistics Quarterly. World Health Organization.
Chicago-referens (17:e uppl.)Não informado. World Health Statistics Quarterly. Geneva, Suíça: World Health Organization, 1978.
MLA-referens (8:e uppl.)Não informado. World Health Statistics Quarterly. World Health Organization, 1978.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.