@misc{indiciae4c5173809f9f,
  title = {Geologic Map of the Piedmont Hollow Quadrangle, Oregon County, Missouri},
  author = {David J. Weary},
  year = {2008},
  doi = {10.3133/sim2979},
  url = {https://pubs.usgs.gov/publication/sim2979},
  note = {Source identifier: sim2979}
}