1. See for instance an impressive recent review article by Loktev, V.M. (1996), Mechanisms of high-T, supeconductivity of copper oxides, Fiz. Nizk. Temp.
22, 3–45 [Low Temp. Phys.
22, 1–32], and references therein; and also Proceedings of the International Conference “Superconductivity. Physical Aspects” (Kharkov, Ukraine, 1995) in the Special Issues of Fiz. Nizk. Temp.
22 (5, 6) 1996 [Low Temp. Phys.
22 (5, 6) 1996].
2. Calvani, P. (1996) Infrared optical properties of high-T, cuprates, in M. Acquarone (ed.), High Temperature Superconductivity: Models and Measurements, World Scientific, Singapore, pp.233–268.
3. I. Bozovic and D. van der Marel (eds.) (1996) Spectroscopic Studies of Superconductors, Proceedings SPIE - the International Society of Optical Engineering, Vol. 2696, SPIE, Bellingham.
4. Perkins, J.D., Graybeal, J.M., Kastner, M.A., Birgeneau, R.J., Falck, J.P.,and Greven, M. (1993) Mid-infrared optical absoption in undoped lamellar copper oxides, Phys. Rev. Lett. 71, 1621.
5. Perkins, J.D., Kleinberg, D., Kastner, M.A., Birgeneau, R.J., Endoh, Y., Yamada, K., and Hosoya, S. (1995) Infrared optical excitations in La2NiO4, Phys. Rev. B 52, R9863–9866.