@article{9794,
  author = {R. Lang and Peter Bender},
  title = {Analytic Approximation for the Saturation Behavior of OH Emission Regions},
  year = {1973},
  journal = {The Astrophysical Journal},
  volume = {180},
  pages = {647},
  month = {Jan-02-1973},
  issn = {0004-637X},
  url = {http://articles.adsabs.harvard.edu/full/1973ApJ...180..647L},
  doi = {10.1086/151994},
}