Weakly nonlinear localization for a 1-D FPU chain with clustering zones F. Martínez-Farías, P. Panayotaros and A. Olvera Eur. Phys. J. Special Topics, 223 13 (2014) 2943-2952 Published online: 10 December 2014 DOI: 10.1140/epjst/e2014-02307-7