1. A. A. Samarskii and A. N. Tikhonov, “On representation of the waveguide field as a sum of TE and TM fields,” Zh. Teor. Phys. 18 (7), 959–970 (1948) (see also A. A. Samarskii, Selected Works by A.A. Samarskii (Maks, Moscow, 2003) [in Russian]).
2. A. G. Sveshnikov and I. E. Mogilevskii, Mathematical Problems in Diffraction Theory (Mosk. Gos. Univ., Moscow, 2010) [in Russian].
3. K. Zhang and D. Li, Electromagnetic Theory for Microwaves and Optoelectronics (Springer, Berlin, 2007).
4. W. C. Chew, http://wcchew.ece.illinois.edu/chew/course/tgwAll20121211.pdf.
5. A. G. Sveshnikov, “A substantiation of a method for computing the propagation of electromagnetic oscillations in irregular waveguides,” USSR Comput. Math. Math. Phys. 3 (2), 413–429 (1963).