1. M. Scherer and P. Turowski, Cryogenics
18:515 (1978).
2. W. H. Cherry and J. T. Gittleman, Solid-State Electron. 1:287 (1960).
3. R. F. Broom and E. H. Rhoderick, Br. J. Appl. Phys. 11:292 (1960).
4. V. V. Altov, M. G. Kremlev, V. V. Sytchev, and V. B. Zenkevitch, Cryogenics
13:420 (1973).
5. L. Dresner, J. R. Miller, and G. W. Donaldson, Proceedings of the 6th Symposium on Engineering Problems of Fusion Research, IEEE, New York (1976), p. 266.