1. R Leibscher,Neue Hutte 14 (1969) 651.
2. W. F. Zelezny, J. H. Foreman and G. T. Wagner, AIME Conference Paper, New York, Feb. 1960.
3. G. H. Turner,Research 4 (1951) 246.
4. K. D. Gielow, M. S. Thesis, University of Missouri-Rolla (1971).
5. C. J. Krauss, private communication.