1. Kaufman, F., and Kelso, J. R., J. Chem. Phys., 32, 301 (1960).
2. Shaw, T. M., in Formation and Trapping of Free Radicals (edit. by Bass, A. M., and Broida, H. P.), 47 (Academic Press, New York, 1960).
3. Brown, R. L., J. Phys. Chem., 71, 2492 (1967).
4. Kaufman, F., Chemical Reactions in Electrical Discharges, Adv. in Chem. Series, No. 80, 29 (A.C.S., Washington).
5. Fehsenfeld, F. C., Evenson, K. M., and Broida, H. P., Rev. Sci. Instrum., 36, 294 (1965).