The nature of the methanol maser ring G23.657–00.127 - II. Expansion of the maser structureA. Bartkiewicz, A. Sanna, M. Szymczak, L. Moscadelli, H. J. van Langevelde and P. WolakA&A, 637 (2020) A15DOI: https://doi.org/10.1051/0004-6361/202037562
