@article{17663,
      author       = "Stellingwerf, D.A. and XIII. Congress of the International
                      Society for Photogrammetry, Helsinki 1976. Commission VII",
      title        = "Mean Annual Volume Growth from Sequential Volume
                      Determination on Permanent Aerial Photographic Plots,
                      Benessalah  ",
      year         = "1976",
      note         = "separát, 1 sv.",
}