1. J. Stringer,Rev. High-Temp. Mater. 1, 255 (1973).
2. C. H. McLintock and J. Stringer,J. Inst. Met. 90, 190 (1961?1962).
3. J. Stringer,J. Electrochem. Soc. 112, 1083 (1965).
4. J. Stringer and R. K. Hughes, unpublished work.
5. J. Stringer, Proc. Journ�es Int. d'Etudes sur l'Oxid. des Met., Brussels (1965), p. 195.