Ivanov, S., A. Bogolyubov, and B. Sestroretskii. “Method of Impedance Analog of Electromagnetic Space for Solving Initial Boundary Value Problems of Electrodynamics”. Numerical Methods and Programming (Vychislitel’nye Metody I Programmirovanie), vol. 9, no. 17, Sept. 2008, pp. 274-0, https://en.num-meth.ru/index.php/journal/article/view/318.