@article{9344,
  author = {H. Saraph and M. Seaton},
  title = {Electron densities in planetary nebulae},
  year = {1970},
  journal = {Monthly Notices of the Royal Astronomical Society},
  volume = {148},
  chapter = {367},
  pages = {367-381},
  url = {http://adsabs.harvard.edu/full/1970MNRAS.148..367S},
  doi = {10.1093/mnras/148.3.367},
  note = {JILA Pub. 618},
}