1. See, for example, Sorokin, P. P., and Stevenson, M. J., I.B.M. J. (Jan. 1961). Johnson, L. F., and Nassau, K., Proc. Inst. Rad. Eng., 1704 (Nov. 1961). Kaiser, W., and Garrett, C. G. B., Proc. Sec. Quantum Elec. Cong. (1961). Snitzer, E., Phys. Rev. Letters, 7, 444 (1961).
2. Wybourne, B. G., J. Chem. Phys., 36, 2301 (1962).
3. Magno, M. S., Dissertation, Johns Hopkins Univ. (1957).
4. Griederich, A., Hellwege, K. H., and Lammermann, H., Z. Physik, 158, 251 (1960).
5. Crosswhite, H. M. (private communication).