1. Siegbahn, K., Nordling, C., Fahlman, A., Nordberg, R., Hamrin, K., Hedman, J., Johansson, G., Bergmark, T., Karlsson, S.-E., Lindgren, I., Lindberg, B.: ESCA-Atomic, molecular, and solid state structure studied by means of electron spectroscopy. Uppsala: Almqvist & Wiksells 1967.
2. Siegbahn, K.: Phil. Trans. Roy. Soc. (London) A 268, 33 (1970).
3. Kanter, H.: Phys. Rev. B 1, 522 (1970).
4. Katrich, G. A., Sarbei, O. G.: Soviet Phys.-Solid State (English Transl.) 3, 1181 (1961).
5. Powell, C. J.: Surface Science 44, 29 (1974); another survey in which lower electron energies are emphasized is I. Lindau und W. E. Spicer, J. Elect. Spectry. 3, 409 (1974).