Ucapan Terima kasih
* Brikke, François, dan Bredero, Maarten. [http://www.washdoc.info/docsearch/title/117705 Linking technology choice with operation and maintenance in the context of community water supply and sanitation: A reference document for planners and project staff] atau ([http://www.who.int/water_sanitation_health/hygiene/om/wsh9241562153/en/ atau alternative link]) alternative link. World Health Organization and IRC Water and Sanitation Centre. Jenewa, Swiss 2003.* [http://www.bvsde.paho.org/eswww/tecapropiada/otratec/waterlin/tb22.pdf Waterlines: Technical Brief 22] or atau ([http://www.washdoc.info/docsearch/title/116333 alternative link]).