1. P R. Billingshurst, C. A. Brookes, andD. Tabor,Proc. Phys. Soc. (1966) 253.
2. F. P. Bowden andC. A. Brookes,Proc. Roy. Soc. A295 (1966) 244.
3. C. A. Brookes andJ. B. O'Neill, Proc. Symp. Anisotropy in Refractory Compound Single Crystals, Vol. 2 (ed. F. W. Vahldiek and S. A. Mersol). (New York, Plenum Press, 1968) p. 291.
4. J. B. O'Neill, Ph.D. Dissertation, University of Bradford, 1970.
5. C. A. Brookes, J. B. O'Neill, andB. A. W. Redfern,Proc. Roy. Soc. A322 (1971) 73.