@misc{indiciaeab233a0e3b8a,
  title = {Bentonite deposits in marine Cretaceous formations, Hardin district, Montana and Wyoming},
  author = {Maxwell M. Knechtel and Sam H. Patterson},
  year = {1956},
  doi = {10.3133/b1023},
  url = {https://pubs.usgs.gov/publication/b1023},
  note = {Source identifier: b1023}
}