@misc{indiciaea5122c695a44,
  title = {Direct radiometric measurement of the uranium and thorium series in equilibrium by gamma-ray scintillation spectrometer},
  author = {Patrick M. Hurley},
  year = {1955},
  doi = {10.3133/tei499},
  url = {https://pubs.usgs.gov/publication/tei499},
  note = {Source identifier: tei499}
}