1. 8) Y. MATSUSHITA and K. GOTO: Tetsuto-Hagane Overseas, 4 (1964) 2, p.129
2. 9) Y. MATSUSHITA and K. GOTO: J. Faculty of Engineering, University of Tokyo (B), 27 (1964), p.217
3. 10) Y. MATSUSHITA and K. GOTO: Symposium on Thermodynamics by International Atomic Energy Agency at Wien, Austria, July 22-27 (1965)
4. 11) Wayne L. WORRELL: Measurement of the Thermodynamic Stabilities of the Niobium and Tantalum Oxides Using a High-Tempereture Galvanic Cell (June) 1965 by Private Cornmunication
5. 12) J. E. ELLIOTT and M. GLEISER: Thermochemistry for Steelmaking, 1 (1960), Addison-Wesley Publishing Co.