1. A. D. Grigor’ev and V. B. Yankevich, Resonators and Microwave Resonator Slow-Wave Structures. Numerical Methods for Calculation and Design (Radio i Svyaz’, Moscow, 1984) [in Russian].
2. I. A. Nakrap and A. N. Savin, in Proc. 23th Int. Crimean Conf. on Microwave and Telecommunication Technology (CriMiCo’2013), Sevastopol, Ukraine, Sept. 9–13, 2013 (Weber, Sevastopol, 2013), p. 203.
3. I. A. Nakrap and A. N. Savin, in Proc. 22th Int. Crimean Conf. on Microwave and Telecommunication Technology (CriMiCo’2012), Sevastopol, Ukraine, Sept. 10–14, 2012 (Weber, Sevastopol, 2012), p. 187.
4. I. A. Nakrap, A. N. Savin, and K. P. Vakhlaeva, in Proc. 20th Int. Crimean Conf. on Microwave and Telecommunication Technology (CriMiCo’2010), Sevastopol, Ukraine, Sept. 13–17, 2010 (Weber, Sevastopol, 2010), p. 255.
5. A. N. Savin, Candidate’s Dissertation in Mathematics and Physics (Saratov. Gos. Univ., Saratov, 2003).