1. G. Ciovati, in: K.-J. Kim (Ed.), Proceeding Pushing the Limits of RF Supercond. Workshop, Argonne IL, ANL-05/10, 2005, p. 52.
2. B. Visentin, see Ref. [1], p. 94.
3. Proceeding 38th Eloisatron Workshop, Erice, 1999;Halbritter,2001
4. Proceeding 10th Workshop on RF Supercond., Tsukuba, Japan, 2001,2003
5. Intrinsic type-2 superconductivity in pure niobium