Probing isotopic ratios at z = 0.89: molecular line absorption in front of the quasar PKS 1830-211S. Muller, M. Guélin, M. Dumke, R. Lucas and F. CombesA&A, 458 2 (2006) 417-426DOI: https://doi.org/10.1051/0004-6361:20065187
