1. K.B. Unser,Atomkernenergie-Kerntechnik
47, 48 (1985).
2. J. Borer and R. Jung,Diagnostics CERN/LEP-BI/84-14,Geneva, Switzerland (1984).
3. H. Koch, H Mühling, R. Neubert and W. Vodel,Proc. 7th Int. Symp. on Weak Superconductivity '94, Polygrafia SAV, Bratislava, Slovakia, 396 (1994).
4. V. Zrubec,Cryogenics
36, 427 (1996).
5. K. Grohman, H.D. Hahlbohm, D. Hechtfischer and H. Lübbig,Cryogenics
16, 423 (1976).