The first GeV flare of the radio-loud narrow-line Seyfert 1 galaxy PKS 2004–447 A. Gokus, V. S. Paliya, S. M. Wagner, S. Buson, F. D’Ammando, P. G. Edwards, M. Kadler, M. Meyer, R. Ojha, J. Stevens and J. Wilms A&A, 649 (2021) A77 Published online: 13 May 2021 DOI: 10.1051/0004-6361/202039378