1. D.A. Shirley, Ed. Electron Spectroscopy, North Holland - Amsterdam, Amer. Elsevier, N.Y. 1972.
2. Kai Siegbahn, et al, ESCA Atomic Molecular and Solid State Structure Studied by Means of Electron Spectroscopy, Almquist and Wiksells Boktryckeri AB, Uppsala, 1967.
3. W.E. Spicer and C.N. Berglund, Rev. Sci. Inst., 35 1665 (1964).
4. R.E. Eden, Rev. Sci. Inst. 41, 252 (1970).
5. See for example, F.Abeles, Ed., Proc. of Intern. Colloq. on Optical Properties and Electronic Structure of Metals and Alloys, Paris, 1965 ( North-Holland, Amsterdam; John Wiley, New York ).