1. 1) Y. Mishima: Annual Report of Engineering Research Institute, University of Tokyo, 20 (1962), 165 (in Japanese);
2. Y. Mishima and M. Yamashita: Annual Report of Engineering Research Institute, University of Tokyo, 21 (1962), 94 (in Japanese).
3. 2) Most of the published works have been reviewed in the recent papers, e.g. I. Pfeiffer: Z. Metallk., 56 (1965), 465;
4. M. Nakagawa: Japan. J. Appl. Phys., 4 (1965), 760.
5. 3) O. Nickel: Z. Metallk., 48 (1957), 417;