1. R. Keller, B. J. Welch and A. T. Tabereaux, Light Metals 1990, pp. 333–40 (1990).
2. C. G. Goodes and S. H. Algie, Light Metals 1989, pp. 199–206 (1989).
3. R. Keller, Light Metals 1982, pp. 295–8 (1982).
4. R. Keller, Extended Abstr. III Alum. Symp., Banska Bystrica, CSSR, 1976.