1. See, e.g., Proceedings of the International Conference on High-Temperature Superconductors and Materials and Mechanism of Superconductivity, Interlaken, Switzerland, Physica C 153–155 (1988).
2. See, e.g., H. Keller, IBM J. Res. Develop. 33, 314 (1989), and references quoted therein.
3. H. Keller, B. Pümpin, W. Kündig, W. Odermatt, B.D. Patterson, J.W. Schneider, H. Simmler, S. Connell, K.A. Müller, J.G. Bednorz, K.W. Blazey, I. Morgenstern, C. Rossel, and I.M. Savic, Physica C 153–155, 71 (1988).
4. B. Pümpin, H. Keller, W. Kündig, W. Odermatt, B.D. Patterson, J.W. Schneider, H. Simmler, S. Connell, K.A. Müller, J.G. Bednorz, K.W. Blazey, I. Morgenstern, C. Rossel, and I.M. Savic, Z. Phys. B - Condensed Matter 72, 175 (1988).
5. K.A. MüUer, M. Takashige, and J.G. Bednorz, Phys. Rev. Lett. 58, 1143 (1987).