1. K. Ishii, N. Akimoto, S. Tashiro and H. Igarashi, J. Eur. Ceram. Soc., 19, 1157-1160 (1999);
2. K. Ishii, T. Yamada, S. Tashiro and H. Igarashi, Trans. Mater. Res. Soc. of Japan, 24, 23-26 (1999).
3. 2) T. Wada, T. IEE Japan, 119-A, 246-253 (1998)[in Japanese].
4. 3) Y. Tanaka, "Piezoelectric Ceramics and its Applications," Denpa-Shinbun Co., Tokyo (1974) pp. 38-41 [in Japanese].
5. 4) D. Guyomar, N. Aurelle and L. Eyraud, J. Phys. III France, 7, 1197-1201 (1997).