1. D. M. Ernst, in IEEE Conference Record of 1970 Thermionic Conversion Specialist Conference: Papers Presented at the 9th Annual Conference, Miami Beach, 1970 (IEEE, New York, 1970), pp. 492–497.
2. J. Dunlay, S. Matsuda, and V. Poirier, in Proceedings of the 3rd International Conference on Thermionic Electrical Power Generation, Julich, 1972, Vol. 3, pp. 1085–1090.
3. V. P. Kobyakov and A. G. Kalandarishvili, Zh. Tekh. Fiz. 68(8), 131 (1998) [Tech. Phys. 43, 997 (1998)].
4. V. P. Kobyakov, Zh. Tekh. Fiz. 66(7), 169 (1996) [Tech. Phys. 41, 726 (1996)].
5. V. P. Kobyakov, Kristallografiya 41, 552 (1996) [Crystallogr. Rep. 41, 523 (1996)].