1. W. B. Blumenthal:The Chemical Behavior of Zirconium, Van Nostrand, New York, N.Y., 1958.
2. H. F. Reichard and R. H. Nielsen:J. Metals, 1976, vol. 28, no. 3, p. 28.
3. H. A. Wilhelm and R. A. Foos: U.S. Atomic Energy Commission, ISC, 1954, p. 458.
4. D. F. Peppard: U.S. Patent 2,923,607, February 2,1960.
5. J. Hure and R. Saint-James:Proc. Int. Conf. Peaceful Uses Atomic Energy, Geneva 1955, United Nations, N.Y., 1956, vol. 8, p. 551.