1. 1) T. Shiokawa: 69th General Meeting of Ductile Iron Society, Lynchburg, (1980); 1st Int. Conf. on ADI, Chicago, (1984), p. 107.
2. 2) K. Hornung and W. Hauke: 1st Int. Conf. on ADI, Chicago, (1984), p. 185.
3. 3) N. S. Chang, C. C. Grupke and G. M. Tarajos: World Conf. on ADI, Bloomingdale, (1991), p. 271.
4. 4) K. Okazaki, H. Asai, M. Tokuyoshi and H. Kusunoki: World Conf. on ADI, Bloomingdale, (1991), 288.
5. 5) M. Tada, T. Kurikuma, Y. Makimura, S. Mizuno, T. Sekiguchi and H. Ishikawa: World Conf. on ADI, Bloomingdale, (1991), p. 300.