1. R. E. Ogilvie inProceedings of the Third Symposium on Electron Beam Technology, edited by R. Bakish (Alloyd Corp., Boston, 1961), p. 238.
2. R. E. Ogilvie (private communication).
3. A. T. Nelms, “Energy Loss and Range of Electrons and Positrons,” Supplement to National Bureau of Standards, Circular 577, (30 June 1958).
4. Ernst Weber,Electromagnetic Fields(John Wiley & Sons, Inc., New York, 1950), Vol. 1.
5. J. C. Maxwell,A Treatise on Electricity and Magnetism(Clarendon Press, Oxford, England, 1892), 3rd. ed., Vol. 1, p. 443.