Não informado. Public Health Service Publications. U.S. Department of Health Education and Welfare.
Chicago-referens (17:e uppl.)Não informado. Public Health Service Publications. Washington: U.S. Department of Health Education and Welfare.
MLA-referens (8:e uppl.)Não informado. Public Health Service Publications. U.S. Department of Health Education and Welfare.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.