1. A. V. Gusev and V. N. Rudenko,Zh. Eksp. Teor. Fiz. 72, 1217 (1977) [Sov. Phys.?JETP 45, 637 (1977)].
2. B. Cabrera, inFuture Trends in Superconducting Electronics (AIP Conference Proceedings No. 44, New York, 1978), p. 73.
3. K. K. Likharev and B. T. Ulrich,Dynamics of Josephson Junction Circuits; Basic Theory (Moscow Univ. Publ., Moscow, 1978).
4. R. P. Giffard, inFuture Trends in Superconducting Electronics (AIP Conference Proceedings No. 44, New York, 1978), p. 11.
5. L. D. Jackel and R. A. Buhrman,J. Low Temp. Phys. 19, 201 (1975).