1. S. Sato, T. Nomura, A. Sato, Dielectric ceramic composition and electronic device. (TDK Corporation (Tokyo JP), United States Patent 1999)
2. Y.-S. Jung, et al, Mater. Res. Bull. 37,1633–1640 (2002)
3. H. Kobayashi, et al, Dielectric ceramic composition and electronic device. (TDK Corporation (Tokyo JP), United States Patent 2002)
4. T. Li, et al, Mater. Lett. 44, 1–5 (2000)
5. A. Yamaji, et al, J. Am. Ceram. Soc. 60, 97–101 (1977)