1. Rep. BNWL-2127;SW Ahlstrom,1977
2. Duschek, A and Hochrainer, A. 1968. Grundzuge der Tensorrechnung in analytischer Darstellung. Springer-Verlag.
3. Kinzelbach, W. 1986. Groundwater Modelling. Developments in Water Science 25. Elsevier.
4. Feller, W. 1971. An Introduction to Probability Theory and Its Applications. Volume II, second edition. John Wiley, New York.
5. Papoulis, A., 1965. Probability, Random Variables and Stochastic Processes. McGraw-Hill Kogakusha, Tokyo, 583 pp.