1. UN World Assessment Program 2015 http://www.unesco.org/new/en/natural-sciences/environment/water/wwap/wwdr/2015-water-for-a- sustainable-world/.
2. California Department for Water Resources http://www.water.ca.gov/waterconditions/declaration.cfm.
3. Morrison, J., Tooms, S. and Rogers, D., District Metered Areas Guidance Notes. IWA Publishing, London, United Kingdom, 2007.
4. Thornton, J Managing leakage by managing pressure - A practical approach, IWA Water 21 October 2003.
5. McKenzie, R, Lambert, A Best Practice Performance Indicator - A practical approach, IWA Water 21 August 2004.