1. 1) S. Sakai: IEICE, 90 (2007) 544-548. (in Japanese)
2. 2) K. Oyama, Y. Matsuba: JIPE, 9 (2006) 538-545. (in Japanese)
3. 3) T. Ishii, H. Fujiwara, M. Saito, T. Honma: Copper and copper alloy: Journal of Japan Research Institute for Advanced Copper-Base Materials and Technologies, 55 (2016) 101-107. (in Japanese)
4. 4) P. Pawlow: z. Phys. Chem., 655 (1909) 1-35.
5. 5) T. Ishii, H. Nishikubo, H. Fujiwara: Furukawa Dennkou Jihou, 135 (2016) 51-56. (in Japanese)