659 20160222141719.0 SIDCimport-758 Clette, F. 2013 2013-11-xx Revisiting the Sunspot Number: re-calibration and futures extensions STCE Lefèvre, L. Wauters, L. ISSI Workshop on The Solar Activity Cycle: Physical Causes and Consequences, Bern, 11/11/2013 Invited CTALKINVI