Onufriyenko, L. M., V. P. Chumachenko, and Y. V. Chumachenko. “ON JUSTIFICATION OF A MATHEMATICAL MODEL FOR A PLANAR JUNCTION OF THREE WAVEGUIDES. PART I. E-PLANE PROBLEM”. Radio Electronics, Computer Science, Control, no. 3, June 2015, doi:10.15588/1607-3274-2015-3-1.