@article{7221,
  author = {D. Winget and H. Van Horn and Carl Hansen},
  title = {The nature of the ZZ Ceti oscillations - Trapped modes in compositionally stratified white dwarfs},
  year = {1981},
  journal = {The Astrophysical Journal},
  volume = {245},
  pages = {L33},
  month = {Jan-04-1981},
  issn = {0004-637X},
  url = {http://articles.adsabs.harvard.edu/full/1981ApJ...245L..33W},
  doi = {10.1086/183516},
}