1. For a recent review see C. L. Briant and S. K. Banerji:Int. Met. Rev., 1978, no. 4, p. 164.
2. C. D. Gelatt and H. Ehrenreich: Private communication, Harvard University, Cambridge, MA, 1978; see also C. D. Gelatt, H. Ehrenreich, and R. E. Watson:Phys. Rev. B, 1977, vol. 15, p. 1613.
3. C. J. McMahon, Jr., V. Vitek, and G. R. Belton:Scr. Met., 1978, vol. 12, p. 785.
4. E. D. Hondros:Proc. Roy. Soc. (London), 1965, vol. A286, p. 479.
5. M. P. Seah and C. Lea:Phil. Mag., 1975, vol. 31, p. 627.