@article{9645,
  author = {Carl Hansen and John Cox and M. Herz},
  title = {Secular Stability of Pure Helium Stars},
  year = {1972},
  journal = {Astronomy and Astrophysics},
  volume = {19},
  chapter = {144},
  pages = {144-154},
  url = {http://articles.adsabs.harvard.edu/full/1972A\%26A....19..144H},
  note = {JILA Pub. 841},
}