@misc{indiciae8737504907ca,
  title = {Spectrophotometric determination of traces of lead in igneous rocks},
  author = {C. E. Thompson and H. M. Nakagawa},
  year = {1960},
  doi = {10.3133/b1084f},
  url = {https://pubs.usgs.gov/publication/b1084F},
  note = {Source identifier: b1084F}
}