A study of catalogued nearby galaxy clusters in the SDSS-DR4 - I. Cluster global properties J. A. L. Aguerri, R. Sánchez-Janssen and C. Muñoz-Tuñón A&A, 471 1 (2007) 17-29 Published online: 16 May 2007 DOI: 10.1051/0004-6361:20066478