Rotation measures of radio sources in hot galaxy clusters F. Govoni, K. Dolag, M. Murgia, L. Feretti, S. Schindler, G. Giovannini, W. Boschin, V. Vacca and A. Bonafede A&A, 522 (2010) A105 Published online: 09 November 2010 DOI: 10.1051/0004-6361/200913665