1. Barry, B. M.:M. Sc. Thesis, Department of Mathematics. Kingston, Ontario: Queen's University (1976).
2. Brockett, R. W.:Finite Dimensional Linear Systems. New York: J. Wiley and Sons (1970).
3. Goldberg, R.:Fourier Transforms. Cambridge: Cambridge University Press (1961).
4. Greenberg, J. M., MacCamy, R. C., andMizel, V. I.: On the existence, uniqueness, and stability of solutions of the equation??(u x )u xx +?u xtx =? 0 u tt .Journal of Mathematics and Mechanics,17, 707?728. (1968).
5. Pace, I. S., andBarnett, S.: Comparison of numerical methods for solving Liapunov matrix equations.International Journal on Control,15, 907?915 (1972).