1) J. Völkel and G. Alefeld: Hydrogen in Metals, Ed. by G. Alefeld and J. Völkel, Springer Verlag, (1978), p. 321;
J. Völkel and G. Alefeld: Diffusion in Solids, Ed. by A. S. Nowick and J. J. Burton, Academic Press, N.Y., (1975), p. 260 and references there in.
2) R. W. Lin and H. H. Johnson: Advanced Techniques for Characterizing Hydrogen in Metals, Ed. by N. F. Fiore and B. J. Berkowitz, Metal. Soc. AIME, (1982), p. 105.
3) M. Surkein and R. Heidersback: Advanced Techniques for Characterizing Hydrogen in Metals, Ed. by N. F. Fiore and B. J. Berkowitz, Metal. Soc. AIME, (1982), p. 119.
4) M. A. Pick: Metal Hydrides, Plenum Press, N.Y., (1981), p. 325.