1. Barnothy, J. and Forro, M.: 1936, Nature
138, 325; 1937, Zeits. Physik.
104, 744.
2. Barnothy, J. and Forro, M.: 1939, Phys. Rev. 55, 870; 1940, ibid
58, 744.
3. Benndorf, Dorno, Hess, v.Schweidler and Wulf: 1913, physik. Zeits. 14, 1141; See also page 8 of this book.
4. Blackett, P.M.S.: 1938, Phys. Rev.
54, 973.
5. Forbush, S.E. and Lange, I.: 1948, Researches D. T.M. Carnegie Inst. Washington
14.