1. H. N. Ko, J. Ceram. Soc. Japan, 94, 534 (1986); ibid., 95, 472 (1987).
2. H. N. Ko, J. Mat. Sci. Lett., 6, 175 (1987).
3. H. N. Ko, Proc. of the MRS International Meeting on Advanced Materials, 5, Materials Research Society, Pittsburgh (1989)P.43.
4. H. P. Kirchner and R. M. Gruver, Fracture Mechanics of Ceramics, 1, Plenum Press, New York (1974)P.309.
5. Kyocera, Private communication.