@article{4227,
      author       = "Simonsen, O. and International Union of Geodesy and
                      Geophysics - XII General Assembly Helsinki 25 July - 6
                      August 1960",
      title        = "Closing errors for a part of U. E. L. N. comprising E + P
                      (polygons 4001 - 4012 and 9023 - 9024 and parts of polygons
                      9020 - 9022) calculated by use of both (a) true gravity g at
                      ground surface (b) theoretical standard gravity in zero
                      level  ",
      year         = "1960",
      note         = "1 sv., International Association of Geodesy, International
                      Commission for European Levelling",
}