1. National Materials Advisory Board, “Tantalum and Columbium Supply and Demand”, Publication NMAB-391, National Academy Press, Washington, DC, 1981.
2. I. Kirman and D.H. Warrington:J. Iron Steel Inst., Dec. 1967, pp. 1264-65.
3. D.F. Paulonis, J.M. Oblak, and D.S. Duvall:Trans. ASM, 1969, vol. 62, pp. 611–22.
4. R. Cozar and A. Pineau,Metall. Trans., 1973, vol. 4, pp. 47–59.
5. J. K. Tien and S. Purushothaman: “The Metallurgy of High Temperature Alloys”,Properties of High Temperature Alloys, The Electrochemical Society, Princeton, 1976, pp. 3–41.