Slow sand filtration

Are there any good descriptions of effective systems using slow sand filtration? The following references should be helpful:

• Biosandfilter.org
  Set up by Bushproof, a company that provides socially beneficial products and services specifically tailored for use in developing countries. Provides lots of information on bio-sand filters, including testing, guidelines,
  Contact: Adriaan Mol, director Bushproof Madagascar

• Brikke, F. [et al.] Linking Technology Choice with Operation and Maintenance for Low-Cost Water Supply and Sanitation. The Hague, The Netherlands: IRC; Geneva, Switzerland: WHO; Geneva, Switzerland: Water Supply and Sanitation Collaborative Council. Order information: http://www.irc.nl/page/1839 This guidance manual is designed to help in the selection of rural and low-income water supply and sanitation technologies. Part I provides an introduction to operation and maintenance and the factors influencing technology choice. Part II comprises 50 illustrated fact sheets on various low-cost water supply and sanitation technologies, including water treatment - both household and central systems - (chlorination, slow sand filtration, sedimentation, upflow roughing filtration).
• Centre for Affordable Water and Sanitation Technology (CAWST)
  Their technology page on household technologies contains a description on the biosand filter: how it works, removal of contaminants, effectiveness, operation and maintenance, and advantages and limitations.

The following references refer to out of print documents. They are mentioned here as you might be able to trace them.

• Morgan, P. (1990). Rural Water Supplies and Sanitation. London, UK: Macmillan. 358 pp.: ill. ? Includes index. ISBN 0333485696 [out-of-print]
• Janonis, B.A. [et al.] (1991). Manual of Design for Slow Sand Filtration. Denver, CO, USA: American Water Works Association. 247 pp.: fig., tab. ISBN 0898675510 [out of print]