@misc{indiciaea12d4f5e895e,
  title = {Depositional environment of Upper Cretaceous black sandstones of the Western Interior},
  author = {Robert Stroud Houston and John F. Murphy},
  year = {1977},
  doi = {10.3133/pp994a},
  url = {https://pubs.usgs.gov/publication/pp994A},
  note = {Source identifier: pp994A}
}