Overlapping of acoustic bandgaps using fractal geometries S. Castiñeira-Ibáñez, V. Romero-García, J. V. Sánchez-Pérez and L. M. Garcia-Raffi EPL, 92 2 (2010) 24007 Published online: 15 November 2010 DOI: 10.1209/0295-5075/92/24007