1. E.M. Savitsky, I.V. Burov, L.N. Litvak, Electrical and Emission Properties of Alloys, Nauka, Moscow, Russia, 1978 (in Russian).
2. E. Okress, Crossed-Field Microwave Devices, vol. 1, Academic Press, New York, 1961.
3. I.M. Bronstein, B.S. Friman, Secondary Electron Emission, Nauka, Moscow, Russia, 1969 (in Russian).
4. Electron-beam induced reduction of carbon concentration on BeO and its effects on secondary electron emission