1. L. Klein:J. Metals, 1961, August, pp. 545-47.
2. F. E. Brantley and C. H. Schack: U. S. Bureau of Mines R. I. 6113, 1962.
3. R. Henych, F. Kadlec, and V. Sedlacek :J. Metals, 1965, April, pp. 386-88.
4. N. J. Themlis and P. R. Schmidt:Trans. TMS-AIME, 1967, vol. 239, p. 1313: also, preprint No. 1A-GA-1,1966 AIME Annual Meeting, February 27, 1966.
5. R. D. Pehlke and A. I. Bernent:Trans. TMS-AIME, 1962, vol. 224, pp. 1237–1242.