@misc{indiciaeabfbad3c5302,
  title = {Test of airborne fluorometer over land surfaces and geologic materials},
  author = {George Eimert Stoertz and William R. Hemphill},
  year = {1970},
  doi = {10.3133/ofr70316},
  url = {https://pubs.usgs.gov/publication/ofr70316},
  note = {Source identifier: ofr70316}
}