@article{4590,
  author = {G. Rybicki and David Hummer},
  title = {An accelerated lambda iteration method for multilevel radiative transfer. I - Non-overlapping lines with background continuum},
  year = {1991},
  journal = {Astronomy and Astrophysics},
  volume = {245},
  pages = {171-181},
  month = {05/1991},
  url = {http://articles.adsabs.harvard.edu/full/1991A\%26A...245..171R},
  note = {JILA Pub. 4361},
}