1. Axelsson, A., Iterative Solution Methods, Cambridge Univ. Press. Cambridge, 1994.
2. Bishop, A. B., Introduction to Discrete Linear Controls: Theory and Application. Academic Press, New York, 1975.
3. Cadzow, J. A., Discrete-Time System: An Introduction with Interdisciplinary Applications. Prentice Hall, Englewood Cliffs. 1973.
4. Cadzow, J. A. & Martens, H. R., Discrete-Time and Computer Control Systems, Prentice Hall, Englewood Cliffs, 1970.
5. Studies in Maths. and its Appls;S. K. Godunov,1987