1. I. Langmuir,Collected Works, edited by C. G. Suits (Pergamon Press, Inc., New York, 1961), Vols. 3, 4, 5.
2. D. Bohm inCharacteristics of Electrical Discharges in Magnetic Fields, edited by A. Guthrie and R. K. Wakerling (McGraw-Hill Book Company, Inc., New York, 1949).
3. S. H. Lam, Princeton University, Aero. Eng. Dept., Report No. 681, March 1964.