1. R.B. Thompson, T.A. Gray, J.D. Achenbach and K.Y. Hu, “Ultrasonic Scattering from Intergranular Stress Corrosion Cracks: Derivation and Application of Theory”, EPRI NP-3822, January 1985, Electric Power Research Institute, Palo Alto, Cal.
2. R.B. Thompson and E.F. Lopes, “The Effects of Focussing and Refraction on Gaussian Ultrasonic Beams”, Journal of Nondestructive Evaluation, Vol. 4, No. 2, 1984.
3. B.A. Auld, “General Electromechanical Reciprocity Relations Applied to the Calculation of Elastic Wave Scattering Coefficients”, WAVE MOTION, 1, 1979, p. 3.
4. J.D. Achenbach, Wave Propagation in Elastic Solids, Amsterdam/New York: North Holland Publishing Co., 1973, p. 179.
5. J.D. Achenbach, A.K. Gautesen and H. McMaken, Ray Methods for Waves in Elastic Solids, Boston: Pitman Publishing, Inc. 1982, pp. 243 - 244.