1. Liskovets, O. A., "The method of lines (English Translation)," J. Dif. Eqs., Vol. 1, 1308, 1965.

2. Schulz, U. and R. Pregla, "A new technique for the analysis of the dispersion characteristics of planar waveguides," Archiv Electronik Ubertragungstechnik, (Electronics and Communication), Vol. AEU 34, 169-173, 1980.

3. Pregla, R. and W. Pascher, "The method of lines," Numerical Techniques for Microwave and Millimeter Wave Passive Structures, T. Itoh, (editor), 381-446, J. Wiley Publ., New York, 1989.

4. Pregla, R. and F.-J. Schmuckle, "The method of lines for the analysis of lossy millimeter wave structures (in German)," Kleinheubacher Berichte, Vol. 32, 261-269, 1989.

5. Schrniickle, F.-J. and R. Pregla, "The method of lines for the analysis of lossy planar waveguides," IEEE Trans. Microwave Theory Tech., Vol. 38, 1473-1479, 1990.
doi:10.1109/22.58688

6. Pregla, R., M. Koch, and W. Pascher, "Analysis of hybrid waveguide structures consisting of microstrip and dielectric waveguides," Proc. 17th Eur. Microwave Conf., 927-932, Rome, 1987.

7. Rogge, U. and R. Pregla, "Method of lines for the analysis of strip-loaded optical waveguides," J. Optical Society of America B, Vol. 8, No. 2, 459-463, 1991.
doi:10.1364/JOSAB.8.000459

8. Rogge, U. and R. Pregla, "Method of lines for the analysis of dielectric waveguides," J. Lightwave Technology, Vol. 11, No. 12, 1993.
doi:10.1109/50.257964

9. Feit, M. D. and J. A. Fleck, "Light propagation in graded-index optical fibers," Appl. Opt., Vol. 17, 3990-3998, 1978.
doi:10.1364/AO.17.003990

10. Moore, T. G., J. G. Blaschak, A. Taflove, and G. A. Kriegsmann, "Theory and application of radiation boundary operators," IEEE Trans. Antennas Propagation, Vol. 36, No. 12, 1797-1811, 1988.
doi:10.1109/8.14402

11. Pregla, R. and J. Gerdes, "New beam-propagation algorithm based on the method of lines," Integrated Photonics Research, Technical Digest Series, Vol. 5, 29-30, 1990.

12. Dreher, A. and R. Pregla, "Analysis of planar waveguides with the method of lines and absorbing boundary conditions," IEEE Microwave Guided Wave Lett., Vol. 1, No. 6, 138-140, 1991.
doi:10.1109/75.91091

13. Pregla, R. and D. Kremer, "Method of lines with special absorbing boundary conditions --- Analysis of weakly guiding optical structures," IEEE Microwave Guided Wave Lett., Vol. 2, No. 6, 239-241, 1992.
doi:10.1109/75.136518

14. Dreher, A. and R. Pregla, "Full-wave analysis of radiating planar resonators with the method of lines," IEEE Transactions on Microwave Theory and Technology, Vol. 41, No. 8, 1993.
doi:10.1109/22.241676

15. Dreher, A., The method of lines and the integral equation technique for the analysis of planar antennas (in German), Vol. 21, No. 116, Ph.D. Dissertation, Fern Universitat, Hagen, VDI-Verlag, 1991.

16. Hadley, G. R., "Transparent boundary condition for beam propagation," Opt. Lett., Vol. 16, No. 9, 624-626, 1991.
doi:10.1364/OL.16.000624

17. Hadley, G. R., "Transparent boundary condition for the beam propagation method," IEEE J. Quantum Electronics, Vol. 28, No. 1, 363-370, 1992.
doi:10.1109/3.119536

18. Gerdes, J. and R. Pregla, "Beam-propagation algorithm based on the method of lines," J. Optical Society of America B, Vol. 8, No. 2, 389-394, 1991.
doi:10.1364/JOSAB.8.000389

19. Gerdes, J. and R. Pregla, "New applications and improvements of the method of lines beam-propagation method," Integrated Photonics Research, Technical Digest Series, Vol. 8, 93, 1991.

20. Gerdes, J., B. Lunitz, D. Benish, and R. Pregla, "Analysis of slab waveguide discontinuities including radiation and absorption effects," Electronic Letters, Vol. 28, 1013 -1014, 1992.
doi:10.1049/el:19920644

21. Pregla, R., J. Gerdes, E. Ahlers, and S. Helfert, "MoL-BPM algorithrns for waveguide bends and vectorial fields," Integrated Photonic Research, Technical Digest Series, Vol. 10, 32-33, 1992.

22. Collin, R. E., Field Theory of Guided Waves, 232-244, Mc Graw-Hill, 1960.

23. Kornatz, A. and R. Pregla, "Increase of the order of approximation and improvement of the interface conditions for the method of lines," IEEE J. Lightwave Technology, Vol. 11, No. 2, 1993.
doi:10.1109/50.212534

24. Lagasse, P., et al., "COST-216 comparative study of S-bend and directional coupler analysis methods," Proc. 16th Eur. Conf. Optical Communication, Vol. 1, 175-178, Nijhoff, Amsterdam, 1990.

25. Worm, S. B., "Analysis of arbitrarily shaped planar microwave stuctures,", Ph.D. Dissertation, FernUniversitat Hagen, 1983 (in German).

26. Gerdes, J., "An efficient analysis of longitudinally varying integrated optical waveguides,", Vol. 21, No. 138, Ph.D. Dissertation, FernUniversitat, Hagen, VDI-Verlag, ISBN 3-18-143821-9, 1993 (in German).

27. Gu, Jing-Son, Numerical analysis of directionally varying optical waveguides, Ph.D. Dissertation, Chapter 6.2, ETH Ziirich, 1991.

28. Pascher, W. and R. Pregla, "Analysis of curved optical waveguides by the vectorial method of lines," Proc. Intl. Conf. Integrated Optics and Optical Fibre Communications, 237-240, Paris, 1991.

29. Deri, R. J. and R. J. Hawkins, "Polarization, scattering and coherent effects in semiconductor Rib waveguide bends," Opt. Letters, Vol. 13, No. 10, 922-924, 1988.
doi:10.1364/OL.13.000922

30. Pregla, R. and E. Ahlers, "Method of lines for analysis of discontinuities in optical waveguides," Electronics Letters, Vol. 29, No. 21, 1845-1846, 1993.
doi:10.1049/el:19931228

31. Ahlers, E. and R. Pregla, "Modelling of Y-branches with the MoL-BPM," Proceedings of the Integrated Photonics Research Topical Meeting, 222-224, San Franzisco, USA, 1994.

32. Ahlers, E. and R. Pregla, "Modeling of Y-branches with the MoL-BPM," Proceedings of the International Symposium on Integrated Optics, EUROPTO series (EOS and SPIE), Lindau, Germany, 1994.

33. Pregla, R. and W. Yang, "Method of lines for analysis of multilayered dielectric waveguides with Bragg gratings," Electronics Letters, Vol. 29, No. 22, 1962-1963, 1993.
doi:10.1049/el:19931306

34. Mustieles, F. J., E. Ballesteros, and F. Hernandez-Gil, "Multi-modal analysis method for the design of passive TE/TM converters in integrated waveguides," IEEE Photonics Letters, Vol. 5, No. 7, 1993.

35. Gerdes, J., S. Helfert, and R. Pregla, "Three-dimensional vectorial eigenmode algorithm for nonparaxial propagation in reflecting optical waveguide structures," Electronics Letters, Vol. 31, No. 1, 65-66, 1995.
doi:10.1049/el:19950031

36. Pregla, R. and E. Ahlers, "Method of lines for analysis of arbitrarily curved waveguide bends," Electronics Letters, Vol. 30, No. 18, 1478-1479, 1994.
doi:10.1049/el:19940997