1. Kossel, Gött. Nachr. Math. Naturw. Kl., 1, 229 (1935); Ann. Phys., 25, 512; 26, 533 (1936); Ergeb. exakt. Naturw., 16, 295 (1937); Borrmann, Ann. Phys., 27, 669; Voges, ibid., 694 (1936); Cauchois and Hulubei, Comptes rend., 206, 181 (1938); etc.
2. Kikuchi, Proc. Imp. Acad. Tokyo, 4, 354 (1928); Jap. J. Phys., 5, 83 (1928); Thomson and Cochrane, "Theory and Practice of Electron Diffraction" (Macmillan, London, 1939), 111 et seq.
3. Fujiwara and Onoyama, H ros ma J. Sci., 9, 115 (1939); Onoyama, ibid., 125; Fujiwara, ibid., 233.
4. Linnik, NATURE, 124, 946 (1929).