1. ‘Numerical analysis of homogeneously filled waveguides by the finite-element method’, Leeds University research report, LU/EE/68/06,
2. Hannaford, C.D.: ‘Finite-difference/variational method for in-homogeneous, isotropic or anisotropic waveguides’, 1967, Ph.D. thesis, University of Leeds
3. Marcuvitz, N.: Waveguide handbook, (McGraw-Hill 1951)