1. R. Pompe, L. Hermansson andR. Carlsson,Sprechsaal 115 (1982) 1098.
2. Idem, ?Engineering with Ceramics?, edited by R. W. Davidge (British Ceramic Society, Stoke-on-Trent, 1982) p. 65.
3. A. Atkinson, P. J. Leatt andA. J. Moulson,J. Mater. Sci. 7 (1972) 482.
4. C. P. Gazzara andD. R. Messier,Ceram. Bull. 59 (1977) 777.
5. D. R. Clarke,Ultramicros. 4 (1979) 33.