@misc{indiciae27c32b200675,
  title = {A spectrographic method for determining trace amounts of lead in zircon and other minerals},
  author = {C. L. Waring and Helen Worthing},
  year = {1952},
  doi = {10.3133/tei216},
  url = {https://pubs.usgs.gov/publication/tei216},
  note = {Source identifier: tei216}
}