1. Haertling GH (1999) J Am Cer Soc 82:797
2. Phule PP, Risbud HS (1990) J Mater Sci 25:1169
3. Daniels J, Härdtl KH, Wernicke R (1978/1979) Philips Tech Rev 38:73
4. Lines ME, Glass AM (1979) Principles and applications of ferroelectric and related materials. Clarendon Press, Oxford
5. Moulson AJ, Herbert JM (1990) Electroceramics. Chapman and Hall, London UK, p 69