1. Skoskiewicz, T.: Phys. Status Solidi A,11, K123 (1972)
2. Stritzker, B.: Z. Phys.268, 261 (1974)
3. Stritzker, B., Buckel, W.: Z. Phys.1, 257 (1972)
4. Review papers with additional references: Stritzker, B., Wühl, H.: In. Topics in Applied Physics. Hydrogen in Metals II, Vol. 29, Alefeld, G., Völkl, J. (eds.), p. 243, Berlin, Heidelberg, New York: Springer-Verlag 1979
5. Westlake, D.G., Satterthwaite, C.B., Weaver, J.H.: Phys. Today31, 32 (1978)