@misc{indiciaefb6443489633,
  title = {Natural gamma aeroradioactivity of parts of the Los Angeles region, California},
  author = {K. G. Books},
  year = {1962},
  doi = {10.3133/gp309},
  url = {https://pubs.usgs.gov/publication/gp309},
  note = {Source identifier: gp309}
}