1. Ababou , R. L. W. Gelhar D. McLaughlin Three-dimensional flow in random porous media Cambridge 1988
2. Aldama , A. A. C. Paniconi An analysis of the convergence of Picard iterations for implicit approximations of Richards' equation Proceedings of the IX International Conference on Computational Methods in Water Resources T. F. Russell R. E. Ewing C. A. Brebbia W. G. Gray G. F. Pinder 521 528 Billerica, Mass. 1992
3. Conjugate gradient type methods for unsymmetric and inconsistent systems of linear equations;Axelsson;Linear Algebra Appl.,1980
4. A functional iteration technique for solving the Richards equation applied to two-dimensional infiltration problems;Brutsaert;Water Resour. Res.,1971