@article{21698,
      author       = "Williams, E. and International Cartographic Association and
                      Working Session and Business Meeting 21-26 Aug. 1973,
                      Budapest",
      title        = "The Ordonance Survey System for Pre-Editing and Digitising
                      Large Scale Plans  ",
      year         = "1973",
      note         = "1 seš.",
}