Low-frequency study of two clusters of galaxies: A2744 and A2219 E. Orrù, M. Murgia, L. Feretti, F. Govoni, G. Brunetti, G. Giovannini, M. Girardi and G. Setti A&A, 467 3 (2007) 943-954 Published online: 13 March 2007 DOI: 10.1051/0004-6361:20066118