1. 1R. L. Coble, W. D. Kingery, H. K. Bowen, and D. R. Uhlmann ; p.200 in, Introduction to Ceramics , 2d ed. Wiley & Sons, New York. 1976 .
2. 2F. F. Lange ; unpublished work.
3. 3A. G. Evans, R. L. Coble, and R. M. Cannon , Preliminary Reports, Memoranda and Technical Notes or the DARPA Materials Research Council, University of Michigan, Ann Arbor. Mich., 1976 .
4. 4C. W. Lau, A. S. Argon, and D. M. R. Taplin ; pp.595 -601 inFracture, 1977 . Vol. 2. Universily of Waterloo Press, Waterloo, Ontario, Canada, 1977 .