1. V. A. Greshnikov, and Yu. B. Drobot, Acoustic Emission [in Russian], Moscow (1976).
2. V. N. Ionov and P. M. Ogibalov, Stresses in Solids with Pulse Loading [in Russian] Moscow (1975).
3. I. M. Babakov, Theory of Vibrations, Moscow (1965).
4. L. Bergman, Ultrasound [in Russian], Moscow (1957).
5. A. Hald, Statistical Theory with Engineering Applications, Wiley (1952).