1) Y. Fukaya, M. Sueda, T. Matsumoto, T. Kobayashi, S. Shiraishi, S. Hata and H. Ohsawa, Quarterly J. Japan Welding Soc., 11, 341-47 (1993) [in Japanese].
2) S. Tanaka, Ceramics Japan, 25, 200-04 (1990) [in Japanese].
3) O. Kamigaito, Ceramics Japan, 25, 183-89 (1990) [in Japanese].
4) T. Narita, S, Hayashi and S. Hata, J. Japan Inst. Metals, 60, 884-89 (1996) [in Japanese].
5) T. Takashima and T. Narita, Zairyo-to-Kankyo, 44, 300-05 (1995) [in Japanese].