@article{Clette:3677,
      author        = "Clette, Frédéric  and Cliver, Edward W. and Lefèvre,
                       Laure and Svalgaard, Leif and Vaquero, José M.",
      title         = "{Revision of the Sunspot Number(s)}",
      year          = "2015",
      note          = "News article",
}