1. Stratton, J. A., Electromagnetic Theory, McGraw-Hill, New York, 1941. See also Stratton, J. A. and L. J. Chu, ``Diffraction theory of electromagnetic waves," Phys. Rev., Vol. 56, 99-107, 1939.
2. Schelkunoff, S. A., "Kirchoff’s formula, its vector analogue, and other field equivalence theorem," Proceedings of the Theory of Electromagnetic Waves Symposium, 43-57, Interscience Publishers, New York, 1951.
3. Franz, V. W., "Zur formulierung des huygensschen prinzips," Z. Naturforsch., A, Vol. 3a, 500-506, 1948.
4. Tai, C. T., Generalized Vector and Dyadic Analysis, 2nd Ed., IEEE Press and Oxford University Press, New York and oxford, 1997.
5. Webster, A. G., Partial Differential Equations of Mathematical Physics, 2nd Ed., 208, Dover Publications, New York, 1955.
6. Schelkunoff, S. A., "Some equivalence theorems of electromagnetics and their applications to radiation problems," B.S.T.J., Vol. 15, 92-112, 1936.
7. Tai, C. T., Dyadic Green Functions in Electromagnetic Theory, 2nd Ed., IEEE Press, New York, 1994.
8. Tai, C. T., "A concise formulation of Huygens’s principle for the electromagnetic field," IRE Trans. on Antennas and Propagation, Vol. 9, 634, 1960.
9. Tai, C. T., "Kirchoff theory: scalar, vector, or dyadic?," IEEE Trans. Antennas Propagat., Vol. AP-20, No. 1, 114-115, 1972.
10. Sancer, M. I., "An analysis of the vector Kirchoff equations and the associated boundary line charge," Radio Science, (New Series), Vol. 3, 141-144, 1968.
11. Meixner, J., "Die kantenbedingung in der theorie der beugung elektromagnetischer wellen und volkommen leitenden ebenem schirmen," Ann. Phys., Vol. 441, 2-9, 1949.
12. Collin, R. E., Field Theory of Guided Waves, IEEE Press and Oxford Univ. Press, New York and Oxford, 1991.
13. Sommerfeld, A., Optics, Academic Press, New York, 1954.
14. Levine, H. and J. Schwinger, "On the theory of electromagnetic wave diffraction by an aperture in an infinite plane conducting screen," Theory of Electromagnetic Wave Symposium, 1-38, Interscience Publications, New York, 1951.