1. M. Nekab, A. Pape, Ch. Heitz, Intern J. PIXE, 5 (1995) No. 1, 11.
2. E. Merzbacher, H. W. Lewis, Encyclopedia of Physics, Vol. 34, Springer Verlag, Berlin 1958, p. 166.
3. J. F. Ziegler, J. P. Biersack, U. Littmark The Stopping and Ranges of Ions in Matter, Vol. 1, Pergamon Press, New York, 1985.
4. R. D. Dewey, R. S. Mapes, T. W. Reynolds, Progress in Nuclear Energy Series IX, Vol. 9, Pergamon Press, New York, 1969, p. 321.
5. F. Hopkins, R. Brenn, A. R. Whittemore, N. Cue, V. Dutkiewicz, Phys. Rev. A, 11 (1975) 1482.