1. F. I. Shamray and P. Ya. Saldau: Bulletin Academy of Science, (1937) p. 631.
2. G. Grube, L. Mohr, and W. Breuning: Ztsch. für Elektrochemie (1935) 41, p. 880.
3. H. Vosskühler: Metallwirtschaft (1937) 16, p. 907.
4. G. Komorowsky and A. Maximov: Ztsch. für Kristallographie (1935) 92, p. 275; also Journal of Technical Physics (1935) 5, p. 1343.
5. P. Albert, M. Caron, and G. Chaudron: Comptes Rendus (1951) 233, p. 1108.