@misc{indiciae524bd469ba38,
  title = {Natural gamma aeroradioactivity of the District of Columbia and parts of Maryland, Virginia, and West Virginia},
  author = {S.K. Neuschel},
  year = {1965},
  doi = {10.3133/gp475},
  url = {https://pubs.usgs.gov/publication/gp475},
  note = {Source identifier: gp475}
}