1. Black and Veatch. Consulting Engineers . 1964 . Report on water works improvements for Lincoln, Nebraska, an unpublished report . Black and Veatch Consulting Engineers, Kansas City, Missouri.
2. Black and Veatch Consulting Engineers . 1967 . Cost curves for conventional water supply systems. Unpublished data obtained through personal interview . Black and Veatch Consulting Engineers, Kansas City, Missouri.
3. Richard N. DeVries, 1969 . An application of optimization in planning the use of multiple water sources that supply municipal water demands. Unpublished Ph.D. dissertation . Department of Civil Engineering, Utah State University, Logan, Utah.