1. R. W. DURMAN,British Foundryman 69 (1976) 141.
2. R. S. JACKSON, ibid.67 (1974) 34.
3. J. T. H. PEARCE, PhD thesis, Aston University (April 1982).
4. G. L. POWELL,Met. Forum 3 (1980) 37.
5. J. VAN DEN BOOMGAARD and L. R. WOLFE,J. Cryst. Growth 15 (1972) 11.