@article{9643,
  author = {Carl Hansen},
  title = {A Relation between Thermal Diffusion and Secular Time Scales in Simple Stellar Envelopes},
  year = {1972},
  journal = {Astronomy and Astrophysics},
  volume = {19},
  chapter = {71},
  pages = {71-75},
  url = {http://adsabs.harvard.edu/full/1972A\%26A....19...71H},
  note = {JILA Pub. 846},
}