1. ISO/ASTM 52792 (West Conshohocken PA: ASTM, 2015).
2. C. Deckard, private communication, 2015.
3. C. Deckard, (Masters thesis, Univ. Texas Austin, 1986).
4. J. Frenkel, J. Phys. (USSR) 9, 385 (1945).
5. G.W. Scherer, J. Am. Cer. Soc. 69, 206 (1986).