1. M.J. Adams, An Introduction to Optical Waveguide (Wiley, New York, 1981)
2. A. Snyder, J. Love, Optical Waveguide Theory (Springer, New York, 1983), p. 735
3. L.A. Vainshtein Electromagnetic Waves (Sovetskoe Radio, 1957) (in Russian)
4. D. Marcuse Light Transmission Optics (Krieger Pub Co, 1989)
5. V. Shestopalov, Yu. Shestopalov, Spectral Theory and Excitation of Open Structures (IET, London, 1996)