Asymmetric local displacements in the Bi2Sr2CaCu2O8+δ superconductorN. L. Saini, A. Lanzara, A. Bianconi and H. OyanagiEur. Phys. J. B, 18 2 (2000) 257-261DOI: https://doi.org/10.1007/s100510070056