1. Cardone G., Nazarov S. A., and Taskinen J., “Spectra of open waveguides in periodic media,” J. Funct. Anal., 269, No. 8, 2328–2364 (2015).
2. Bakharev F. L. and Nazarov S. A., “Gaps in the spectrum of a waveguide composed of domains with different limiting dimensions,” Sib. Math. J., 56, No. 4, 575–592 (2015).
3. Carini J. P., Londergan J. T., and Murdock D. P., Binding and Scattering in Two-Dimensional Systems: Applications to Quantum Wires, Waveguides, and Photonic Crystals, Springer-Verlag, Berlin (1999) (Lect. Notes Phys.).
4. Birman M. Sh. and Solomyak M. Z., Spectral Theory of Selfadjoint Operators in Hilbert Space, D. Reidel Publ. Co., Dordrecht (1987).
5. Gelfand I. M., “Expansion in eigenfunctions of an equation with periodic coefficients,” Dokl. Akad. Nauk SSSR, 73, 1117–1120 (1950).