1. Bear, J.: Hydraulics of Groundwater. McGraw-Hill, New York (1979)
2. Benzi, M., Cullum, J.K., Tůma, M.: Robust approximate inverse preconditioning for the conjugate gradient method. SIAM J. Sci. Comput. 22, 1318–1332 (2000)
3. Benzi, M., Tůma, M.: A sparse approximate inverse preconditioner for nonsymmetric linear systems. SIAM J. Sci. Comput. 19, 968–994 (1998)
4. Benzi, M., Tůma, M.: A comparative study of sparse approximate inverse preconditioners. Applied Numerical Mathematics 30, 305–340 (1999)
5. Benzi, M., Marin, J., Tůma, M.: A two-level parallel preconditioner based on sparse approximate inverses. In: Kincaid, D.R., Elster, A.C. (eds.) Iterative Methods in Scientific Computation IV, New Brunswick, New Jersey, USA. IMACS Series in Computational and Applied Mathematics, vol. 5, pp. 167–178 (1999)