1. H. Padamsee, IEEE Trans. Mag., 21 (2) [1985] 1007
2. P. Kneisel, J. Less Common Metals, 139 [1988] 179
3. “ Advances in the purification of niobium by solid-state gettering with titanium “, H. Safa, D. Moffat, B. Bonin, F. Koechlin, Journal of Alloys and Compounds, 232 (1996) p. 281–288
4. “Nb purification by Ti gettering”, H. Safa, D. Moffat, F. Koechlin, E. Jacques, Y. Boudigou, Proc. of the 7th Workshop on RF Superconductivity, Gif-sur-Yvette, France (Oct. 1995), p. 649
5. “ Degradation of niobium superconducting RF cavities during cooling time “, B. Aune & al, LINAC Conference, Albuquerque (USA, 1990)