Identifying changing jets through their radio variability I. Liodakis, T. Hovatta, M. F. Aller, H. D. Aller, M. A. Gurwell, A. Lähteenmäki and M. Tornikoski A&A, 654 (2021) A169 Published online: 27 October 2021 DOI: 10.1051/0004-6361/202141053