1. C. M. Diaz and F. D. Richardson:Trans. Inst. Mining Met. (London), 1967, vol.76, p. C196.
2. R. J. Fruehan and F. D. Richardson:Trans. Met. Soc. AIME, 1969, vol. 245, p. 1721.
3. D. R. Young: Ph.D. Thesis, Univ. London, 1965.
4. K. P. Abraham:Trans. Indian Inst. Metals, 1969, vol. 22, p. 5.
5. K. T. Jacob and J. H. E. Jeffes:Trans. Inst. MiningMet. (London), 1971, vol. 80, p.C32.