Dovbnya, A., V. Zakutin, and N. Reshetnyak. “Direct-Action Accelerator Based on the Magnetron Gun With a Secondary-Emission Cathode and Iits Aplication in Radio-Technologies”. East European Journal of Physics, no. 1017(3), Sept. 2012, pp. 85-89, https://periodicals.karazin.ua/eejp/article/view/13704.