@misc{indiciae8dd20d9f38de,
  title = {Physiographic provinces and sections in western Oklahoma and adjacent parts of Texas},
  author = {N. M. Fenneman},
  year = {1923},
  doi = {10.3133/b730d},
  url = {https://pubs.usgs.gov/publication/b730D},
  note = {Source identifier: b730D}
}