@misc{indiciae38d67bfd7bbc,
  title = {Tritium rainout over the United States in 1962 and 1963},
  author = {G.L. Stewart and C.M. Hoffman},
  year = {1966},
  doi = {10.3133/cir520},
  url = {https://pubs.usgs.gov/publication/cir520},
  note = {Source identifier: cir520}
}