1. R. K. Hopkins: U. S. Patent 2,191,479–80. M. W. Kellogg Co., 1940.
2. R. M. Parke and John L. Ham: The Melting of Molybdenum in the Vacuum Arc. AIME Trans., 1947, vol. 171, p. 461; Metals Technology, September 1946.
3. J. L. Ham: First Annual Report, Office of Naval Research Contract N80nr-78700, 1950. Climax Molybdenum Company. Arc-Cast Molybdenum Base Alloys.
4. W. J. Kroll: Ductile Titanium. Trans., Electrochemical Soc., 1940, vol. 78, p. 35.
5. W. J. Kroll, A. W. Schlechten, and L. A. Terkes: Ductile Zirconium from Zircon Sand. Trans., Electrochemical Soc., 1946, vol. 89, p. 263.