@misc{indiciaef9ad1cc70289,
  title = {Uranium, radium, and selected metallic-element analyses of spring water and travertine samples from the Grand Canyon, Arizona},
  author = {J.E. Peterson and S.E. Buell and R. A. Cadigan and J.K. Felmlee and C.S. Spirakis},
  year = {1977},
  doi = {10.3133/ofr7736},
  url = {https://pubs.usgs.gov/publication/ofr7736},
  note = {Source identifier: ofr7736}
}