@misc{indiciae98117ad1331f,
  title = {The determination of small amounts of rare earths in phosphate rocks},
  author = {Claude L. Waring and Henry Mela},
  year = {1952},
  doi = {10.3133/tei239},
  url = {https://pubs.usgs.gov/publication/tei239},
  note = {Source identifier: tei239}
}