T. Burokas and S. Štaras, “Properties of Helical and Serpentine Slow-Wave Systems Containing Dielectric Holders”, ELEKTRON ELEKTROTECH, vol. 53, no. 4, Apr. 2004, Accessed: Feb. 08, 2026. [Online]. Available: https://eejournal.ktu.lt/index.php/elt/article/view/10908