@InProceedings{SCI:Mag2004a,
  author =    "M. Magnor and G. Kindlmann and C.D. Hansen and N.
              Duric",
  title =     "Constrained Inverse Volume Rendering for Planetary
              Nebulae",
  booktitle = c-VIS2004,
  pages =     "83--90",
  year =      "2004",
  keywords =  "scalar field methods, volume rendering, simian,
              inverse constrained volume rendering",
  url =       "http://www.sci.utah.edu/publications/magnor04/Magnor_Vis2004.pdf",
}