1. F. W. Saris in Physics of Electronic and Atomic Collisions VII ICPEAC, (North-Holland Publishing Company, Amsterdam, 1972) 181. This paper contains an excellent review of the subject.
2. Inner-Shell Ionization Phenomena and Future Applications, edited by R. W. Fink, S. T. Manson, I. M. Palms and P. Venugopala Rao, U. S. ATomic Energy Commission Report No. CONF-720404 (1973). See invited papers by W. Brandt, T. M. Kavanagh, E. Merzbacher, D. I. Nagle, P. Richard and F. W. Saris. There are also many contributed papers in this report.
3. Heavy-Ion Summer Study, edited by S. T. Thornton, U. S. Atomic Energy Commission Report No. CONF-720669 (1973). See papers by P. Richard and E. Merzbacher.
4. W. Brandt in Atomic Physics 3, edited by S. S. Smith, G. K. Walters and L. M. Volsky (Plenum Press, 1973) 155.
5. J. D. Garcia, R. J. Fortner and T. M. Kavanagh, Rev. Mod. Phys. 45, 111 (1973).