1. Superconducting Machines and Devices, Large Systems Applications (S. Foner and B. B. Schwartz, eds.), Springer Science+Business Media New York (1974)
2. H. Brechna, Superconducting Magnet Systems Springer-Verlag, Munich (1973).
3. R. P. Reed, R. P. Mikesell, and A. F. Clark, in: Advances in Cryogenic Engineering, Vol 22, Springer Science+Business Media New York (1976), p. 463.
4. Magnetic Corporation of America and Westinghouse Electric Corporation, private communication.