@misc{indiciae0604f946d8cb,
  title = {Cambrian through Mississippian rocks of the Powder River basin, Wyoming, Montana, and adjacent areas},
  author = {David L. Macke},
  year = {1993},
  doi = {10.3133/b1917m},
  url = {https://pubs.usgs.gov/publication/b1917M},
  note = {Source identifier: b1917M}
}