1. K. Becker,Z. Physik 40 (1926) 37.
2. T. A. Taylor andR. M. Jones, in ?Silicon Carbide, a High-Temperature Semiconductor? edited by J. R. O'Connor and J. Smiltens (Pergamon, Oxford, 1960) p. 147.
3. P. Popper andI. Mohyuddin, in ?Special Ceramics 1964? edited by P. Popper (Academic Press, London, 1965) p. 45.
4. D. Clark andD. Knight, Royal Aircraft Establishment, Technical Report RAE-TR-65049, [AD464397] (1965).
5. E. L. Kern, D. W. Hamill, H. W. Deem andH. D. Sheets,Mater. Res. Bull. 4 (1969) S25.