@article{6851,
  author = {Roy Garstang},
  title = {New Formula for Optimum Magnification and Telescopic Limiting Magnitude},
  year = {1999},
  journal = {Journal of the Royal Astronomical Society of Canada},
  volume = {93},
  pages = {80},
  month = {04/1999},
  url = {http://adsabs.harvard.edu/full/1999JRASC..93...80G},
  note = {JILA Pub. 6247},
}