1. D. BRINKMANN, in Proceedings of the International Seminar on Solid State Ionic Devices, edited by B. V. R. Chowdari and S. Radha Krishna, Singapore, 18th?23rd July (World Scientific, Singapore, 1988) p. 25.
2. S. NARENDER REDDY, A. SADANANDA CHARY, K. SAIBABU and T. CHIRANJIVI,Solid St. Ionics 34 (1989) 73.
3. S. NARENDER REDDY, A. S. CHARY, T. CHIRANJIVI and K. SHAHI, ibid.42 (1990) 101.
4. K. SAIBABU and T. CHIRANJIVI, ibid.13 (1984) 7.
5. L. HEYNE, in ?Mass transport in solids?, edited by F. Beniere and C. R. A. Catlow (Plenum Press, New York, 1981) p. 425.