1. Hogarth, C.A. and J. Blitz, “Techniques of Non-Destructive Testing”, London: Butterworths (1960).
2. Carlin, B., “Ultrasonics”, New York: McGraw-Hill (1960).
3. Goldman, R.C., “Ultrasonic Technology”, New York: Reinhold (1962).
4. Krasil’nikov, V.A., “Sound and Ultrasonic Waves”, Israel Program for Scientific Translations, Jerusalem (1963).
5. McMaster, R.C., “Nondestructive Testing Handbook”, Vol. II, New York: Ronald (1963).