1. B. Henderson, ?Defects in Crystalline Solids?, (Edward Arnold, London, 1972).
2. F. A. Kröger, ?The Chemistry of Imperfect Crystals?, North-Holland, Amsterdam, 1964).
3. W. Van Gool, ?Principles of Defect Chemistry in Crystalline Solids?, (Academic Press, London, 1966).
4. R. J. Brook, in ?Electrical Conductivity of Ceramics and Glass: A?, edited by N. M. Tallan (Dekker, New York, 1974) p. 179.
5. B. J. Wuensch, in ?Mass Transport Phenomena in Ceramics?, edited by A. R. Cooper and A. H. Heuer, (Plenum, New York, 1975).