1. G. Piatti, G. Pellegrini and R. Trippodo, Proceedings of the 6th International Conference on Light Metals, Leoben, Vienna, 1975 (Aluminium Verlag. Düsseldorf, 1976) p. 45.
2. Idem, J. Mater. Sci. 11 (1976) 186.
3. R. Grimes, A. J. Cornish and R. G. Butler, Proceedings of the 7th International Conference on Light Metals, Loeben, Vienna, 1981 (Aluminium Verlag, Düsseldorf, 1982) p. 302.
4. R. Grimes, ?Shaping Metals for the Eighties? (Metallurgical Society Meeting, London, 1981).
5. R. Matera, G. Piatti and K. N. Street, Aluminium 49 (1973) 335.