@article{24467,
      author       = "Wassef, A. M. and International Union of Geodesy and
                      Geophysics - XII General Assembly Helsinki 25 July - 6
                      August 1960",
      title        = "Principles and Methods of Statistical Analysis of Levelling
                      Errors  ",
      year         = "1960",
      note         = "1 sv., International Association of Geodesy, Special Study
                      Group No. 3, 1 příl.",
}