1. R. P. Feynman: Quantum Electrodynamics (Benjamin, New York 1961)
2. H. A. Bethe, J. Goldstone: Proc. R. Soc. London A 238, 551 (1957)
3. H. P. Kelly: Advances in Theoretical Physics, Vol. 2, ed. by K. A. Brueckner (Academic Press, New York 1968) pp. 75-169
4. M. Ya. Amusia: Many-body Effects in Electron Atomic Shells (A. F. Ioffe Physical-Technical Institute Publications, Leningrad 1968) pp. 1-144 in Russian
5. M. Ya. Amusia: X-Ray and Inner-Shell Processes, AIP Conf. Proc. 389, ed. by R. L. Johnson, H. Schmidt-Böking, B. F. Sonntag (AIP Press, Woodbury, New York 1997) pp. 415-430