@article{Lefèvre:3014,
      author        = "Lefèvre, L. and Aparicio, A. J. P. and Gallego, M. C. and
                       Vaquero, J. M.",
      title         = "{An Early Sunspot Catalog by Miguel Aguilar for the Period
                       1914 - 1920}",
      year          = "2016",
      note          = "Sunspot Number special Issue",
}