@article{Clette:5845,
      author        = "Clette, Frédéric and Lefèvre, Laure and Bechet, Sabrina
                       and Ramelli, Renzo and Cagnotti, Marco",
      title         = "{Reconstruction of the Sunspot Number Source Database and
                       the 1947 Zurich Discontinuity}",
      year          = "2021",
}