Não informado. (1968). World Health Statistics Report. World Health Organization.
Lua i Stíl Chicago (17ú heag.)Não informado. World Health Statistics Report. Geneva, Suíça: World Health Organization, 1968.
Lua MLA (8ú heag.)Não informado. World Health Statistics Report. World Health Organization, 1968.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.