1. Honda, M., and Arnold, J. R., Handbuch der Physik., 46/2, 613 (1967).
2. Arnold, J. R., Honda, M., and Lal, D., J. Geophys. Res., 66, 3519 (1961).
3. Lingenfelter, R. E., Rev. Geophys., 1, 35 (1963).
4. Libby, W. F., Radiocarbon Dating (University of Chicago Press, 1955).
5. Goel, P. S., and Kohman, T. P., Science, 136, 875 (1962).