1. The lightning discharge;Bruce;J. Inst. Electr. Eng. London,1941
2. The return stroke of the lightning flash to earth as a source of VLF atmospherics;Dennis;J. Res. Natl. Bur. Stand., Sect. D,1964
3. Jackson, J. D., , Classical Electrodynamics, 5th ed. chap. 9 John Wiley, New York, 1966,
4. Jones, D. S., , The Theory of Electromagnetism, chap. 3 Pergamon, New York, 1964,
5. Jordan, E. C., , K. G., Balmain, , Electromagnetic Waves and Radiating Systems, chap. 11 Prentice-Hall, Englewood Cliffs, N.J., 1968,