@article{27047,
      author       = "Simonsen, O. and Intern. Comm. for European Levelling",
      title        = "Remarks to calculation of closing errors "sigma" "gama" 0
                      "delta" h for three netparts of UELN  ",
      year         = "1960",
      note         = "Dar M. Delonga 20.1. 1964. - 1 sv.",
}