@misc{indiciaef57c23c25c7b,
  title = {The Geologic Time Spiral - A Path to the Past},
  author = {Joseph Graham and William Newman and John Stacy},
  year = {2008},
  doi = {10.3133/gip58},
  url = {https://pubs.usgs.gov/publication/gip58},
  note = {Source identifier: gip58}
}