@misc{indiciae734452271440,
  title = {Preliminary geologic map of the Spring Valley 30' x 60' quadrangle, Missouri},
  author = {R. C. Orndorff and R.W. Harrison},
  year = {1997},
  doi = {10.3133/ofr97434},
  url = {https://pubs.usgs.gov/publication/ofr97434},
  note = {Source identifier: ofr97434}
}