@article{7595,
      author       = "Corten, F.L.J.H. and XIII. Congress of the International
                      Society for Photogrammetry, Helsinki, 1976. Commission IV",
      title        = "Economy in Aerial Survey by Means of the ITC Photnav System
                       ",
      year         = "1976",
      note         = "1 sv.",
}