[1]           M. Ohtaka, “Analysis of the guided modes in the anisotropic dielectric rectangular waveguides”, Trans. Inst. Electron. Commun. Eng. Japan, Vol J64-C, pp. 674-681, Oct 1981.

[2]           Yilong Lu and F. Anibal Fernandez, “An Efficient Finite Element Solution of Inhomogeneous Anisotropic and Lossy Dielectric Waveguides”, IEEE Trans. Microwave Theory Tech., vol. MTT- 41, pp. 1215-1223, June/July. 1993.