Global Health and Education Foundation (2007). "Conventional Coagulation-Flocculation-Sedimentation". Safe Drinking Water is Essential. National Academy of Sciences. मूल से से 7 अक्तूबर 2007 को पुरालेखित।. अभिगमन तिथि: 2007-12-01. {{cite web}}: Check date values in: |archivedate= (help)
Global Health and Education Foundation (2007). "Conventional Coagulation-Flocculation-Sedimentation". Safe Drinking Water is Essential. National Academy of Sciences. मूल से से 7 अक्तूबर 2007 को पुरालेखित।. अभिगमन तिथि: 2007-12-01. {{cite web}}: Check date values in: |archivedate= (help)