W. L. Bragg and E. J. Williams: Proc. Roy. Soc. A145 (1934) 699; ibid. 151 (1935) 540; ibid. 152 (1935)231.
H. A. Kramers: Commun. Kammerlingh Onnes Lab. Suppl. 83 (1963) 14; W. Opechowski: Physica 4(1937) 181.
M. Hattori, K. Adachi and H. Nakano: J. Phys. Soc. Japan 26 (1969) 642; ibid. 35 (1973) 1025.
H. Nakano and M. Hattori: Progr. theor. Phys. 49 (1973) 1752; H. Kimura: J. Phys. Soc. Japan 36 (1974) 1280; S. Homma and H. Nakano: Progr. theor. Phys. 54 (1975) 19; M. Yamashita and