Não informado. (1976). Water quality bulletin. World Health Organization, Collaborating Centre on Surface and Ground Water.
Chicago-referens (17:e uppl.)Não informado. Water Quality Bulletin. Ontario, Canada: World Health Organization, Collaborating Centre on Surface and Ground Water, 1976.
MLA-referens (8:e uppl.)Não informado. Water Quality Bulletin. World Health Organization, Collaborating Centre on Surface and Ground Water, 1976.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.