1. Starace, A.F.: Theory of atomic photoionisation. Handbuch der Physik XXXI. Berlin, Heidelberg, New York: Springer 1982
2. Mott, N.F., Massey, H.S.W.: The theory of atomic collisions. Oxford: Clarendon Press 1965;
3. Massey, H.: Atomic and molecular collisions. London: Taylor and Franas 1979
4. For a review see: Kelly, H.P.: Many-body theory of photoionisation processes. Phys. Scr., Proceedings of the 8th International Conference on ?Vacuum Ultraviolet Physics?, Lund 1986
5. For a review see: Domcke, W.: XIVth International Conference on the Physics of Electronic and Atomic Collisions, 1985