1. N. W. Wyld and K. M. Watson, September 1956 (unpublished).
2. See L. Spitzer, Jr.,Physics of Fully Ionized Gases(Interscience Publishers, Inc., New York, 1956), p. 84.
3. See, e.g., N. F. Mott and H. S. W. Massey,The Theory of Atomic Collisions(Clarendon Press, Oxford, England, 1949) 2nd ed., p. 245.
4. R. D. Richtmyer,Difference Methods for Initial-Value Problems(Interscience Publishers, Inc., New York, 1957), p. 101.