1. Nerazrushayushchii kontrol’/Spravochnik v 7 t. (Nondestructive Testing/A Handbook in 7 Vols.), Klyuev, V.V., Ed., Vol. 3: Yermolov, I.N. and Lange, Yu.V., Ul’trazvukovoi kontrol’ (Ultrasonic Testing), Moscow: Mashinostroenie, 2004.
2. Bhardwaj, M.C., Non-Contact Ultrasonic Testing and Analysis of Materials. Smart Materials, Schwartz, M., Ed., Taylor & Francis Group, CRC Press, 2009.
3. Quaegebeur, N., Masson, P., Berry, A., Ardin, C., and D’Anglade, P.-M., Ultrasonic non-destructive testing of cardboard tubes using air-coupled transducers, NDT & E Int., 2018, vol. 93, pp. 18–23.
4. Römmeler, A., Furrer, R., Sennhauser, U., Lübke, B., Wermelinger, J., de Agostini, A., Dual, J., Zolliker, P., and Neuenschwander, J., Air coupled ultrasonic defect detection in polymer pipes, NDT & E Int., 2019, vol. 102, pp. 244–253.
5. Banks, R., O’Leary, R.L., and Hayward, G., Enhancing the bandwidth of piezoelectric composite transducers for air-coupled non-destructive evaluation, Ultrasonics, 2017, vol. 75, pp. 132–144.