@article{4506,
  author = {B. Bohannan and D. Abbott and S. Voels and David Hummer},
  title = {Photospheres of hot stars. IV - Spectral type O4},
  year = {1990},
  journal = {The Astrophysical Journal},
  volume = {365},
  pages = {729},
  month = {Jan-12-1990},
  issn = {0004-637X},
  url = {http://articles.adsabs.harvard.edu/full/1990ApJ...365..729B},
  doi = {10.1086/169526},
}