1. S.C. Abrahams and P.B. Jamieson, private communication.
2. Non-Stoichiometric Compounds;Wadsley,1964
3. L.G. Van Uitert, S. Singh, H.J. Levinstein, J.E. Geusic and W.A. Bonner, Appl. Phys. Letters, to be published.
4. Crystal Growth;Grodkiewicz,1967