1. E. A. Anderson, D. C. Jillson, and S. R. Dunbar:Trans. TMS-AIME, 1953, vol. 197, p. 1191.
2. A.T. Churchman:Proc. Royal Soc. (London), 1954, vol. 226, p. 216.
3. E.J. Rapperport:Acta Met., 1955, vol. 3, p. 208.
4. R. L, Smialek: Ph.D. Thesis, Case Western Reserve University, January 1970.
5. R.D. Schoone and E.A. Fischione:Rev. Sci. Instr., 1966, vol. 37, p. 1351.