1. A. Yu. Emel’yanov, Fiz. Tverd. Tela (St. Petersburg) 43(2), 316 (2001) [Phys. Solid State 43 (2), 329 (2001)].
2. A. L. Roytburd, S. P. Alpay, L. A. Bendersky, V. Nagarajan, and R. Ramesh, J. Appl. Phys. 89(1), 553 (2001).
3. I. P. Pronin, E. Yu. Kaptelov, N. G. Khosina, and V. P. Afanas’ev, Pis’ma Zh. Tekh. Fiz. 30(6), 25 (2004) [Tech. Phys. Lett. 30 (3), 228 (2004)].
4. Youngsung Kim, Wangkyu Lim, and Jaichan Lee, Integr. Ferroelectr. 37, 285 (2001).
5. L. I. Solov’eva, I. E. Obvintseva, M. I. Yanovskaya, K. A. Vorotilov, and V. A. Vasil’ev, Neorg. Mater. 32(7), 866 (1996) [Inorg. Mater. 32 (7), 767 (1996)].