1. Cheng, D. K., Field and Wave Electromagnetics, 2nd Ed., Addison-Wesley Pub. Co., New York, Sydney, 1992.
2. Plonsey, R. and R. Collin, Principles and Applications of Electromagnetic Fields, McGraw-Hill Co., New York, London, 1961.
3. Griffiths, D. J., Introduction to Electrodynamics, Prentice Hall, New Jersey, 1999.
4. Neff, H. P., Basic Electromagnetic Fields, Harper & Row Pub., New York, London, 1981.
5. Lin, W. and H. Jin, "Analytic solutions to the electrostatic problems of two dielectric spheres," J. Appl. Phys., Vol. 67, No. 3, 1160-1166, 1990.
doi:10.1063/1.345713
6. Stoy, R. D., "Solution procedure for the laplace equation in bispherical coordinates for two spheres in a uniform external field: Parallel orientation," J. Appl. Phys., Vol. 65, No. 7, 2611-2615, 1989.
doi:10.1063/1.342791
7. Stoy, R. D., "Solution procedure for the laplace equation in bispherical coordinates for two spheres in a uniform external field: Perpendicular orientation," J. Appl. Phys., Vol. 66, No. 10, 5093-5095, 1989.
doi:10.1063/1.343737
8. Farlow, S. J., Partial Differential Equations for Scientists and Engineers , Dover Pub., New York, 1993.
9. Zachmanoglou, E. C. and D. W. Thoe, Introduction to Partial Differential Equations with Applications, Dover Pub., New York, 1986.