1. http://ndt.net
2. https://www.olympus-ims.com
3. Chen, Y.: The application of TOFD technique on the large pressure vessel. In: Proceedings of the 17th World Conference on NDT, Shanghai, China (2008).
http://ndt.net
4. Charlesworth, J.P., Temple, J.A.: Engineering Applications of Ultrasonic Time-of-Flight-Diffraction. Research Studies Press, Baldock (2001)
5. Silk, M.G., Lidington, B.H.: Defect sizing using using an ultrasonic time delay approach. Br. J. Nondestruct. Test. 3, 33–36 (1974)