1. R. W. Rice, p. 323 in Fracture Mechanics of Ceramics, Ed. by R. C. Bract, D. P. H. Hasselman, and F. F. Lange, Plenum Press, N.Y., 1974.
2. S. W. Freiman, K. R. McKinney, and H. L. Smith, Ibid, p. 639.
3. A. G. Evans, Ibid, p. 17.
4. R. W. Rice and S. W. Freiman, presented at the Sixth International Materials Symposium: Ceramic Microstructures, 1976. Proceedings to be published by John Wiley and Sons (in press).
5. R. W. Rice, in Properties and Microstructure, Ed. by R. K. MacCrone, to be published by Academic Press, New York (in press).