Jukna, T., V. Sinkevičius, L. Šumskienė, and D. Viržonis. “Research of the Electron Gun Cathode Tracking System”. Elektronika ir Elektrotechnika 61, no. 5 (May 20, 2005): 49-52. Accessed October 7, 2022. https://eejournal.ktu.lt/index.php/elt/article/view/10450.