1. See,e.g., T. Egamiet al., these proceedings; A. Bianconiet al., these proceedings.
2. Lattice Effects in High-Tc Superconductors, eds. Y. Bar-Yamet al. (World Scientific, 1992).
3. A. R. Bishop, inStrongly Correlated Electronic Materials, eds. K. Bedellet al. (Addison-Wesley 1994).
4. e.g., J. A. Krumhansl, in [2].
5. e.g., A. Bussmann-Holder, A. R. Bishop,Phys. Rev. B (in press).