8Alareon J, Escribano P. Cr- CaO - SiO2 Based Ceramic Pigments. Br Ceram Trans J, 1984,83:81 - 83
9System CaO·Al2O3·2SiO2 B.F.Osborn and Arnulf Muan, revised and redrawn "Phase Equilibrium Diagram Society and the Edward ortnn, J Ceramic Foundation, 1960"