Nonlinear piezoelectric devices for broadband air-flow energy harvestingY. Bai, Z. Havránek, P. Tofel, C. Meggs, H. Hughes and T.W. ButtonEur. Phys. J. Special Topics, 224 14-15 (2015) 2675-2685DOI: https://doi.org/10.1140/epjst/e2015-02582-8