Não informado. (1976). Advance Data from Vital & Health Statistics. National Center for Health Statistics.
Chicago-referens (17:e uppl.)Não informado. Advance Data from Vital & Health Statistics. Hyattsville, Md: National Center for Health Statistics, 1976.
MLA-referens (8:e uppl.)Não informado. Advance Data from Vital & Health Statistics. National Center for Health Statistics, 1976.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.