1. The Clean Water and Drinking Water Gap Analysis;USEPA,2002
2. ASCE, Report Card for America's Infrastructure 2003 Progress report (2004), http://www.asce.org/reportcard/.
3. Optimal maintenance-related decision making for deteriorating water distribution systems;Li,1992
4. Evaluation of emergency response for sewer infrastructure management;MacLeod,2000
5. An overview of current and developing technologies for pipe condition assessment;Ratliff,2003