1. G. P. Li, Y. Y. Liu, D. Li and Z. Q. Hu, in Eighth Chinese Conference on Titanium, Shanghai (1993) p. 588.
2. D. Han, M. Z. Chao, ibid p. 593.
3. S. M. L. Sastry, T. C. Peng and L. D. Beckerman, Metall. Trans. 15A (1984) 1465.
4. A. Kelley and R. B. Nickolson, (eds) ?Strengthening methods in crystals? (Applied Science Publishers, London, 1971).
5. P. B. Hirsch and F. J. Humphreys, in ?Physics of strength and plasticity? edited by A. S. Argon (MIT Press, Cambridge, MA, 1969).