Discovery of ammonia (9,6) masers in two high-mass star-forming regions Y. T. Yan, C. Henkel, K. M. Menten, Y. Gong, J. Ott, T. L. Wilson, A. Wootten, A. Brunthaler, J. S. Zhang, J. L. Chen and K. Yang A&A, 659 (2022) A5 Published online: 25 February 2022 DOI: 10.1051/0004-6361/202142891