@article{9651,
  author = {D. Lauterborn and S. Refsdal and R. Stabell},
  title = {Stars with Central Helium Burning and the Occurrence of Loops in the H-R Diagram. III. Horizontal Branch Stars},
  year = {1972},
  journal = {Astronomy and Astrophysics},
  volume = {17},
  chapter = {113},
  pages = {113-127},
  url = {http://adsabs.harvard.edu/full/1972A\%26A....17..113L},
  note = {JILA Pub. 767},
}