1. H. Kaiser and P. Rosendahl, Microchimica Acta, 7, 265 (1955).
2. A. I. Dryakhlov and N. K. Rudnevskii, Trudy po Khim. i Khim. Tekh., Gor’kii, No. 2, 12 (1963).
3. N. K. Rudnevskii, A. I. Dryakhlov, et al., Proceedings of the Fourth Ural Spectroscopy Conference [in Russian], Izd. Metallurigya, (1965),p. 66.
4. T. S. Pavlina, Uch. Zap. GGPI (Gor’kii), Ser. Fiz., No. 73, 82 (1967).
5. T. S. Pavlina, Uch. Zap. GGPI (Gor’kii), Ser. Fiz., No. 73, 85 (1967).