@conference{11474,
  author = {David Hummer},
  title = {Radiative Transfer Processes in Planetary Nebulae},
  year = {1968},
  month = {00/1968},
  publisher = {Dordrecht, D. Reidel Pub. Co.},
  address = {Tatranska Lomnica, Czechoslovakia},
  url = {http://articles.adsabs.harvard.edu/full/1968IAUS...34..166H},
  note = {JILA Pub. 334},
}