1. K. Uchino, Ferroelectric Devices (Marcel Dekker, New York, 2000), p. 197
2. S. Ueha, Y. Tomikawa, M. Kurosawa, N. Nakamura, Ultrasonic Motors-Theory and Applications (Clarendon, Oxford, 1993), p. 100
3. G.H. Haertling, J. Am. Ceram. Soc. 4(82), 797–818 (1999)
4. T.S. Glenn, N.W. Hagood, SPIE 3041, 326–338 (1997)
5. Y. Kawai, Jap. J. Appl. 35, 2711–2714 (1996)