3506 20200213143904.0 CTALK-2018-0050 Lefèvre, Laure How to best (better) concatenate sunspot series ? 2017 2017-02-09 STCE SSN workshop Reading UK laure.lefevre@observatoire.be 1225104 http://publi2-as.oma.be/record/3506/files/ReadingLefevreV2.pptx Contributed CTALKCONT