1. Properties of Sintered Si3N4
2. Komeya Katsutoshi , Tokyo Shibawa Electric Co.; private communication.
3. S. R. Billington, J. Chown, A. E. S. White, and P. Popper ; pp.19 -34 inSpecial Ceramics , Vol. 2 . Edited byAcademic Press Inc., LondonandNew York, 1965 .
4. S. Prochazka ; unpublished work.