References
- Lines , M. E. and Glass , A. M. 1977 . Principles and Applications of Ferroelectrics and Related Materials , Oxford : Clarendon Press .
- Jaskiewicz , A. 1962 . Acta Phys. Polon. , 22 : 489
- Jaskiewicz , A. 1965 . Acta Phys. Polon. , 27 : 637