1. A. Catanzaro, G. Arrigoni, M. Palladino and M. Sarracino, SAE Tech. Pap. Series, No. 830583, Detroit, Michigan (1983).
2. M. Memmi, R. Bruno and M. Palladino,Mater. Perform. 2 (1983) 9.
3. S. Kado, S. A. Yusawa and T. Watanabe,Tetsu to Hagane 66 (1980) 790.
4. T. Adaniya,Sheet Metal Ind. Int. 12 (1978) 73.
5. K. Ariga and K. Kanda,Tetsu to Hagane 66 (1980) 797.