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2. 2) H. P. Braendlin and E. T. Mcbee, Advances in Fluorine Chemistry, Vol. 1, p. 1, London Butterworths (1960).
3. 3) C. E. Colburn, Advances in Fluorine Chemistry, Vol. 3, p. 92, London Butterworths (1963).
4. 4) H. C. Miller and F. D. Loomis, Encyclo. Chem. Tech. 3rd edition, “Fluorine Compound Inorganic (Nitrogen)”, Vol. 11, p. 393 (1966).
5. 5) A. Tasaka and N. Watanabe, in: N. Watanabe (Ed.) Fusso to Kogyo II (Fluorine Chemistry and Industry Part II), Chemistry of Inorganic Fluorides-Fluoride Compounds of Nitrogen, Kagaku Kogyosha, p. 1 (1984) [in Japanese].