1. ABPA A. B. P. A. (1999). "1999 Survey of State and Public Water System Cross-Connection Control Programs."
2. AWWA (2011). Water Quality & Treatment: A Handbook on Drinking Water
3. AWWA/PWNS (1995). Summary of Backflow Incidents
4. AwwaRF (2007). Advancing the Science of Water: AwwaRF and Distribution System Water Quality. Awwa Research Foundation.
5. Explaining the occurrence of coliforms in distribution systems