@article{16972,
      author       = "Calvert, C. E. and Ord. Surv. and IAG - EUREF, Anakara, May
                      22 - 25, 1996",
      title        = "Maintaining the height network of Great Britain  ",
      year         = "1996",
      note         = "1 obr. - 1 sv.",
}