1. R. E. NEWNHAM, D. P. SKINNER and L. E. CROSS, Mater. Res. Bull. 13 (1978) 525.
2. K. A. KLICKER, J. V. BIGGERS and R. E. NEWNHAM, J. Amer. Ceram. Soc. 64 (1981) 5.
3. W. A. SMITH, in Proceedings of the 1986 IEEE International Symposium on Applications of Ferroelectrics, Bethlehem, Pennsylvania, 8?11 June 1986 (Institute of Electrical and Electronic Engineers, New York, 1986) p. 249.
4. H. P. SAVAKUS, K. A. KLICKER and R. E. NEWNHAM, Mater. Res. Bull. 16 (1981) 677.
5. H. TAKEUCHI, C. NAKAYA and K. KATAKURA, in Proceedings of the 1984 IEEE Ultrasonics Symposium, Dallas, Texas, 14?16 November 1984 (Institute of Electrical and Electronics Engineers, New York, 1984) p. 507.