1. F. B. Silsbee, R. B. Scott, and F. G. Brickwedde: J. Res. Nat. Bur. Stand. 18, 295 (1937).
2. A fascinating review of the state of knowledge in the early 1960’s about the behavior of superconductors subjected to magnetic fields and electrical currents can be found in the Proceedings of the International Conference on the Science of Superconductivity, Colgate University, Hamilton, New York, August 26–29, 1963, published in: Rev. Mod. Phys. 36, 1–331 (1964).
3. J. Bardeen and M. J. Stephen: Phys. Rev. 140 A1197 (1965).
4. I. Giaever: Phys. Rev. Letters 15, 825 (1965).
5. B. D. Josephson: Phys. Letters 16, 242 (1965).