1. E. M. Levin, H. F. McMURDIE andF. P. Hall, ?Phase Diagrams for Ceramists? (The American Ceramic Society, Columbus, 1956) p. 35.
2. A. Muan andE. F. Osborn, ?Phase Equilibria among Oxides in Steelmaking? (Addison-Wesley, Reading, 1965) p. 18.
3. K. Eagle andD. Winzer,Stahl und Eisen 95 (1975) 847.
4. ASTM card 18-1170.
5. ASTM card I1-695.