@misc{indiciae1d25b1232c38,
  title = {Permian rock units in the Glass Mountains, west Texas},
  author = {G. Arthur Cooper and Richard E. Grant},
  year = {1966},
  doi = {10.3133/b1244e},
  url = {https://pubs.usgs.gov/publication/b1244E},
  note = {Source identifier: b1244E}
}