@misc{indiciae2e6705286ece,
  title = {A spectrographic method for determining the hafnium-zirconium ratio in zircon},
  author = {C. L. Waring and H.W. Worthing},
  year = {1955},
  doi = {10.3133/tei502},
  url = {https://pubs.usgs.gov/publication/tei502},
  note = {Source identifier: tei502}
}