Inferring the evolutionary stages of the internal structures of NGC 7538 S and IRS1 from chemistryS. Feng, H. Beuther, D. Semenov, Th. Henning, H. Linz, E. A. C. Mills and R. TeagueA&A, 593 (2016) A46DOI: https://doi.org/10.1051/0004-6361/201424912
