@misc{indiciae465e575437ec,
  title = {Pennsylvanian and Permian paleogeography, tectonics and stratigraphy in Montana and the Dakotas},
  author = {E. K. Maughan},
  year = {1966},
  doi = {10.3133/ofr6682},
  url = {https://pubs.usgs.gov/publication/ofr6682},
  note = {Source identifier: ofr6682}
}