1. Karttunen, E., Freund, H.U., Fink, R.W.: Phys. Rev. A4, 1695 (1971)
2. Fink, R.W., Jopson, R.C., Mark, Hans, Swift, C.D.: Revs. Modern Phys.38, 513 (1966)
3. Bambynek, W., Crasemann, B., Fink, R.W., Freund, H.U., Mark, Hans, Swift, C.D., Price, R.E., Rao, P.V.: Revs. Modern Phys.44, 716 (1972)
4. McGuire, E.J.: In: Inner Shell Ionization Phenomena and Future Applications, edited by R.W. Fink, S.T. Manson, J.M. Palms, and P.V. Rao (U.S. Atomic Energy Commission, 1973); pp. 662; also Phys. Rev. A5, 1043 (1972)
5. Bhalla, C.P.: J. Phys. (London) B3, 916 (1970)