(3rd ed.) . Prentice Hall . ISBN   0-13-805326-X .   Jackson, John D. (1999). "Appendix on Units and Dimensions". Classical Electrodynamics (3rd ed.) . Wiley . ISBN   0-471-30932-X .   Littlejohn, Robert (Fall 2011). "Gaussian, SI and Other Systems of Units in Electromagnetic Theory" (PDF). Physics 221A, University of