Changes

* [http://www.wateraid.org/uk/what_we_do/sustainable_technologies/technology_notes/244.asp Technology Notes: Handpumps]. WaterAid.

* Reynolds, John, [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CCUQFjAA&url=http%3A%2F%2Fwww.wsp.org%2FUserFiles%2Ffile%2F418200734405_handpumps.pdf&ei=ESKHT7WlOtDRiAKv_qzYDw&usg=AFQjCNHavJgwIhMHXPdby7OV5PiucVA-3Q&sig2=mDpXSceP1rKcazbdG9RBNg A Sustainable Technology: Research and Development During Water Supply and Sanitation Decade]. UNDP - World Bank Water and Sanitation Program, 1992.