1. A. Nougaoui and B. Djafary, Surf. Sci. 185, 154 (1987).
2. Li Xingjiao, Lei Yibing, and L. E. Cross, J. Appl. Phys. 70, 3209 (1991).
3. V. N. Lyubimov and D. G. Sannikov, Kristallografiya 24, 5 (1979) [Sov. Phys. Crystallogr. 24, 1 (1979)].
4. Li Xingjiao, J. Appl. Phys. 61, 2327 (1987).
5. A. S. Sidorkin, Domain Structure in Segnetoelectrics and Congener Materials (Fizmatlit, Moscow, 2000) [in Russian].