Radio halos in nearby (z < 0.4) clusters of galaxies G. Giovannini, A. Bonafede, L. Feretti, F. Govoni, M. Murgia, F. Ferrari and G. Monti A&A, 507 3 (2009) 1257-1270 Published online: 08 October 2009 DOI: 10.1051/0004-6361/200912667