Establishing the evolutionary timescales of the massive star formation process through chemistry G. Sabatini, S. Bovino, A. Giannetti, T. Grassi, J. Brand, E. Schisano, F. Wyrowski, S. Leurini and K. M. Menten A&A, 652 (2021) A71 Published online: 12 August 2021 DOI: 10.1051/0004-6361/202140469