@article{4606,
      author       = "Hanna, Fred M. and 8th Annual International Congress of
                      Photogrammetry, Stockholm, July, 1956",
      title        = "Control Simplified. An Expedient Method of Resolving the
                      Photogrammetric Triangle  ",
      year         = "1956",
      note         = "1 sv., Prepared for the ..",
}