1. Water Rates: An Assessment of Current Issues;Hanke;Jour. AWWA,1975
2. Clark Robert M. Stevie Richard Trygg , Gregory. The Cost of Municipal Water Supply: A Case Study Ofce. Res. & Development, USEPA Cincinnati, Ohio
3. Water Supply Economics;Clark;Jour. ASCE-Urban Planning and Development Div.,1976
4. Clark Robert M. Gillean James I. The Cost of Water Supply Utility Management USEPA Washington, D.C.
5. Cost and Quality of Water Supply;Clark;Jour. AWWA,1977