@article{13711,
      author       = "Marckwardt, Werner and XIII. Congress of the International
                      Society for Photogrammetry, Helsinki, 1976. Commission II",
      title        = "Investigations and Suggestions for Testing Differential
                      Rectifiers Equipped with Devices for Correcting the
                      Influence of Terrain Cross Slope  ",
      year         = "1976",
      note         = "1 sv.",
}