Solar cyclic activity over the last millennium reconstructed from annual 14C data I. G. Usoskin, S. K. Solanki, N. A. Krivova, B. Hofer, G. A. Kovaltsov, L. Wacker, N. Brehm and B. Kromer A&A, 649 (2021) A141 Published online: 28 May 2021 DOI: 10.1051/0004-6361/202140711