The Faraday screen near the nucleus of the CSS quasar 3C 138 W. D. Cotton, D. Dallacasa, C. Fanti, R. Fanti, A. R. Foley, R. T. Schilizzi and R. E. Spencer A&A, 406 1 (2003) 43-50 Published online: 17 November 2003 DOI: 10.1051/0004-6361:20030523