Davide Taibi, Valentina Lenarduzzi, Terhi Kilamo, Stefano Zacchiroli: Open Source Systems - 17th IFIP WG 2.13 International Conference, OSS 2021, Virtual Event, May 12-13, 2021, Proceedings. IFIP Advances in Information and Communication Technology 624, Springer 2021, ISBN 978-3-030-75250-7