American Water Works Association. (1983). Dual water systems. American Water Works Association.
Chicago-referens (17:e uppl.)American Water Works Association. Dual Water Systems. Denver, Colorado: American Water Works Association, 1983.
MLA-referens (9:e uppl.)American Water Works Association. Dual Water Systems. American Water Works Association, 1983.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.