1. Datta, A. N.: Longitudinal propagation of elastic disturbance for linear variation of elastic parameters. Indian J. Theor. Phys.,4, 43 (1956).
2. Sur, S. P.: A note on the longitudinal propagation of an elastic disturbance in a thin inhomogeneous elastic rod. Indian J. Theor. Phys.,9, 61 (1961).
3. Sternberg, E. andJ. G. Chakravorty: On the propagation of shock waves in a non-homogeneous elastic medium. J. Appl. Mech.,26, 528 (1959).
4. Lindholm, U. S. andK. D. Doshi: Wave propagation in an elastic non-homogeneous bar of finite length. J. Appl. Mech.,32 E, 135 (1965).
5. Eason, G.: Wave propagation in inhomogeneous elastic media. Bull. Seism. Soc. Amer.,57, 1267 (1967).