1. Grandia, W.A., Fortunko, C.M.: NDE applications of air-coupled ultrasonic transducers. In: Proceedings of the 1995 IEEE Ultrasonics Symposium, pp. 697–710
2. Hayward, G.: Air coupled NDE. Constraints and solutions for industrial implementation. In: Proceedings of the 1997 IEEE Ultrasonics Symposium, pp. 665–673
3. Bass, H.E., Sutherland, L.C., Zuckerwar, A.J., Blackstock, D.T., Hester, D.M.: Atmospheric absorption of sound: Further developments. J. Acoust. Soc. Am. 97, 680–683 (1995)
4. Kino, G.S.: Acoustic Waves: Devices, Imaging and Analog Signal Processing. Prentice-Hall, Englewood Cliffs (1987)
5. Gomez, T.E., Montero de Espinosa, F.: Bridging the gap of impedance mismatch between air and solid materials. In: Proc. IEEE Ultrasonic Symposium 2000, pp. 1069–1072 (2000)