@article{4649,
      author       = "Beckers, H. and IUGG XVIII General Assembly, 1983, Hamburg",
      title        = "Correction of Past Levelling Surveys in Rheinland-Pfalz for
                      Magnetic Errors. IUGG XVIII General Assembly, 1983, Hamburg 
                      ",
      year         = "1983",
      note         = "1 sv., obr., mapky a tb. v textu",
}