@article{5530,
  author = {P. Cally and T. Bogdan and Ellen Zweibel},
  title = {Umbral oscillations in sunspots: Absorption of p-modes and active region heating by mode conversion},
  year = {1994},
  journal = {The Astrophysical Journal},
  volume = {437},
  pages = {505},
  month = {Jan-12-1994},
  issn = {0004-637X},
  url = {http://articles.adsabs.harvard.edu/full/1994ApJ...437..505C},
  doi = {10.1086/175014},
}