References for the Richards’ Equation Interface
1. J. Bear, Dynamics of Fluids in Porous Media, Elsevier Scientific Publishing, 1972.
2. J. Bear, Hydraulics of Groundwater, McGraw-Hill, 1979.
3. R.A. Freeze, “Three-dimensional, Transient, Saturated-unsaturated Flow in a Groundwater Basin,” Water Resour.Res., vol. 7, no. 2, 1971.
4. M.Th. van Genuchten, “A Closed-form Equation for Predicting the Hydraulic Conductivity of Unsaturated Soils,” Soil Sci. Soc. Am. J., vol. 44, 1980.
5. R.H. Brooks and A.T. Corey, “Properties of Porous Media Affecting Fluid Flow,” J. Irrig. Drainage Div., ASCE Proc., vol. 72 (IR2), 1966.