Michael D. Tocci Tocci, M. D., Kelley, C. T., Miller, C. T., & Kees, C. E. (1998). Inexact Newton methods and the method of lines for solving Richards' equation in two space dimensions. COMPUTATIONAL GEOSCIENCES, 2(4), 291–309. https://doi.org/10.1023/A:1011562522244 Miller, C. T., Williams, G. A., Kelley, C. T., & Tocci, M. D. (1998). Robust solution of Richards' equation for nonuniform porous media. WATER RESOURCES RESEARCH, 34(10), 2599–2610. https://doi.org/10.1029/98WR01673 Kelley, C. T., Miller, C. T., & Tocci, M. D. (1998). Termination of Newton/Chord iterations and the method of lines. SIAM JOURNAL ON SCIENTIFIC COMPUTING, 19(1), 280–290. https://doi.org/10.1137/S1064827596303582 Tocci, M. D., Kelley, C. T., & Miller, C. T. (1997). Accurate and economical solution of the pressure-head form of Richards' equation by the method of lines. ADVANCES IN WATER RESOURCES, 20(1), 1–14. https://doi.org/10.1016/S0309-1708(96)00008-5