@misc{indiciaed9ebf0c74022,
  title = {Airborne Fraunhofer line discriminator (FLD) luminescence imaging systems and its application to exploration problems},
  author = {Robert D. Watson and Arnold F. Theisen and William R. Hemphill},
  year = {1980},
  url = {https://pubs.usgs.gov/publication/70112904},
  note = {Source identifier: 70112904}
}