1) Townley, L. R.: Numerical Models of Groundwater Flow: Prediction and Parameter Estimation in the presence of Uncertainty, MIT Ph. D. thesis, 1983.
2) Carrera, J. and Neuman, S. P.: Estimation of Aquifer Parameters Under Transient and Steady Conditions: 1, 2&3, WRR 22 (2), pp. 199-242, 1986.
3) Cooley, R. L., Konikow, L. F. and Naff, R. L.: Nonlinear-Regression Groundwater Flow Modeling of a Deep Regional Aquifer System, WRR 22 (13), pp. 1759-1778, 1986.