ATLASGAL-selected massive clumps in the inner Galaxy - I. CO depletion and isotopic ratios A. Giannetti, F. Wyrowski, J. Brand, T. Csengeri, F. Fontani, C. M. Walmsley, Q. Nguyen Luong, H. Beuther, F. Schuller, R. Güsten and K. M. Menten A&A, 570 (2014) A65 Published online: 17 October 2014 DOI: 10.1051/0004-6361/201423692