@article{30586,
      author       = "Ballarin, S. and XII Assemblée Génerale de l'UGGI a
                      Helsinki, 1960",
      title        = "The squared maps for medium altitudes of Italy an the
                      limitroph districts, and maps of equal medium cote lines
                      employed for the reduction of gravity measures executed for
                      the construction of the Italian gravimetric map  ",
      year         = "1960",
      note         = "1 sv., 4 vol. map. příl., Italian Geodetic Commission",
}