@article{21318,
      author       = "Ackermann, F. and XIII. Congress of the International
                      Society for Photogrammetry, Helsinki, 1976. Commission III",
      title        = "On the Development in the Field of ISP-Commission III
                      During 1972 - 1976  ",
      year         = "1976",
      note         = "1 sv.",
}