1. Fast Ion Spectroscopy;J. Physique,1979
2. see in particular articles by K.X To et al. (p. 3), S. Bashkin (p. 125), L.J. Curtis (p. 139), K.W. Jones (p. 197) and D.J. Pegg et al. (p. 205).
3. Progress in Atomic Spectroscopy;Andrä,1979
4. Jahresbericht;Müller,1980