1. Acoustic Methods and Means of Control, in:Devices for Nondestructive Testing of Materials and Units. Reference Book,2, [in Russian], Mashinostroyeniye, Moscow (1981), p. 189.
2. I. N. Ermolov,Theory and Practice of Ultrasonic Control [in Russian], Mashinostroyeniye, Moscow (1981), p. 240.
3. R. A. Collacott,Structural Integrity Monitoring, Chapmen & Hall, London (1985).
4. R. Johns Fokozaru,Methods of Nondestructive Testing of Concretes [Russian translation], Stroiizdat, Moscow (1974), p. 278.
5. P. N. T. Wells,Biomedical Ultrasonics, Academic Press, London.