EuPRAXIA Conceptual Design Report R.W. Assmann, M.K. Weikum, T. Akhter, D. Alesini, A.S. Alexandrova, M.P. Anania, N.E. Andreev, I. Andriyash, M. Artioli, A. Aschikhin et al. (234 more) Eur. Phys. J. Special Topics, 229 24 (2020) 3675-4284 Published online: 23 December 2020 DOI: 10.1140/epjst/e2020-000127-8