Langit, R. B. (1997). Water from polluted rivers to be recycled for drinking. Manila Times.
Chicago-referens (17:e uppl.)Langit, Richel B. "Water from Polluted Rivers to Be Recycled for Drinking." Manila Times 1997.
MLA-referens (9:e uppl.)Langit, Richel B. "Water from Polluted Rivers to Be Recycled for Drinking." Manila Times, 1997.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.