@article{Clette:3011,
      author        = "Clette, Frédéric and Lefèvre, Laure and Cagnotti, Marco
                       and Cortesi, Sergio and Bulling, Andreas",
      title         = "{The Revised Brussels-Locarno Sunspot Number (1981 -
                       2015)}",
      year          = "2016",
}