The quest for CN in space - A search with the IRAM 30 m telescope towards IRC+10216 G. W. Fuchs, U. Fuchs, T. F. Giesen and F. Wyrowski A&A, 426 2 (2004) 517-521 Published online: 11 October 2004 DOI: 10.1051/0004-6361:20047177