The EXTraS project: Exploring the X-ray transient and variable sky A. De Luca, R. Salvaterra, A. Belfiore, S. Carpano, D. D’Agostino, F. Haberl, G. L. Israel, D. Law-Green, G. Lisini, M. Marelli et al. (22 more) A&A, 650 (2021) A167 Published online: 25 June 2021 DOI: 10.1051/0004-6361/202039783