@article{10277,
  author = {E. Avrett and J. Vernazza and Jeffrey Linsky},
  title = {Excitation and ionization of helium in the solar atmosphere},
  year = {1976},
  journal = {The Astrophysical Journal},
  volume = {207},
  pages = {L199},
  month = {Jan-07-1976},
  issn = {0004-637X},
  url = {http://adsabs.harvard.edu/full/1976ApJ...207L.199A},
  doi = {10.1086/182212},
}