Discovery of recurrent flares of 6.7 GHz methanol maser emission in Cepheus A HW2 M. Durjasz, M. Szymczak, M. Olech and A. Bartkiewicz A&A, 663 (2022) A123 Published online: 21 July 2022 DOI: 10.1051/0004-6361/202243552