@article{24741,
      author       = "Cross, Paul and Fagir, Ali and FIG and Meeting of FIG Study
                      Group 5B Survey Control Networks, 7th-9th July 1982,
                      Aalborg",
      title        = "Procedures for the First and Second Order Design of
                      Vertical Control Networks  ",
      year         = "1982",
      note         = "Obr. a tb. v textu. - Liter., 1 sv.",
}