1) Lewis, R. B., Connors, E. W., and Koehler, R. F., “A Spectro graph for Charge Distributions on Xerographic Toner”, 4th International Conference on Electrophotography, Washington, D. C, 1981. See also U. S. Patent 4,375,673 and Japanese Laid Open Number 79958/82.
2) Gillespie, T. and Langstroth, CO., “An Instrument for Determining the Electric Charge Distribution in Aerosols”, Canadian J. Chem. 30, 1056 (1952).
3) Megaw, W. J. and Wells, A. C, “Electrical Mobility of Submicron Particles”, Nature 219, 259 (1968).
4) Liu, B. et al.: “Etude de la charge electrique portee par des particules spheriques de latex polystyrene mises en suspension dans l'air”, C. R. Acad. Sc. Paris, 1628 B, 1682 (1969).