Não informado. (1977). Health and Hygiene. Royal Institute of Public Health and Hygiene.
Chicago-referens (17:e uppl.)Não informado. Health and Hygiene. London: Royal Institute of Public Health and Hygiene, 1977.
MLA-referens (8:e uppl.)Não informado. Health and Hygiene. Royal Institute of Public Health and Hygiene, 1977.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.