1. A. A. Podimsky and N. N. Potrakhov, Journal of Physics: Conference Series 808 (2017).
2. G. A. Zhabin, Z. M. Magamednebiev and A. N. Pashkov, Electronic Engineering, Series 1, Microwave Engineering 3(358), 50–58 (2018).
3. R. K. Barik, S. K. Shukla, M. S. Bisht, A. K. Singh and R. S. Raju, Application IJECT 5 (Spl-2), (2014).
4. P. T. Kirstein, G. S. Kino and W. E. Waters, “Space Charge Flow”, McGraw-Hill, (1967).