1. T. Ya. Kosolapova, T. V. Andreeva, T. S. Bartnitskaya, et al., Nonmetallic Refractory Compounds [in Russian], Metallurgiya, Moscow (1985).
2. R. L. Tsai and R. Raj, ?Creep fracture in ceramics containing small amounts of a liquid phase,? Acta Met.,30, 1043?1058 (1982).
3. M. H. Lewis, R. Fung, and R. Taplin, ?Indentation plasticity and fracture of Si3N4 ceramic alloys,? J. Mater. Sci.,16, No. 12, 3437?3446 (1981).
4. W. Wrub, R. Kieffer, and E. Gugel, ?Technologische Untersuchungen in system Si3N4-Al2O3,? Sprechsaal für Keramik Glass Baustoffe,108, No. 13?14, 378?383 (1975).
5. E. Gugel, I. Petzenhauser, and A. Fickel, ?X-ray investigation of the system Si3N4-Al2O3,? Powder Met. Int.,7, No. 2, 66?67 (1975).