Spatially resolved carbon and oxygen isotopic ratios in NGC 253 using optically thin tracersS. Martín, S. Muller, C. Henkel, D. S. Meier, R. Aladro, K. Sakamoto and P. P. van der WerfA&A, 624 (2019) A125DOI: https://doi.org/10.1051/0004-6361/201935106