Offemaria, R. (1999). Potable water: The world's most precious commodity. Manila Times.
Chicago-referens (17:e uppl.)Offemaria, Rodel. "Potable Water: The World's Most Precious Commodity." Manila Times 1999.
MLA-referens (9:e uppl.)Offemaria, Rodel. "Potable Water: The World's Most Precious Commodity." Manila Times, 1999.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.