The depletion of NO in pre-protostellar cores M. Akyilmaz, D. R. Flower, P. Hily-Blant, G. Pineau des Forêts and C. M. Walmsley A&A, 462 1 (2007) 221-230 Published online: 02 November 2006 DOI: 10.1051/0004-6361:20066131