1. Baer, T, in Mass Spectrometry, Specialist Periodical Reports, Vol. 6, Royal Society Chemistry, London, 1981.
2. Rosenstock, H.M., Wallenstein, M.B., Wahrhaftig, A.L., and Eyring, H. Proc. Natl. Acad. Sci. U.S., 38, 667 (1952).
3. Chupka, W.A., J. Chem. Phys., 30 191 (1959).
4. Murad, E. and Inghram, M.G., J. Chem. Phys., 40, 3263 (1964).
5. Brehm, B. and Puttkamer, E.V., Z. Naturforsch, 22a, 8 (1967).