@misc{indiciaec60a51a04534,
  title = {Lower Cretaceous bentonitic strata in southwestern Montana assigned to Vaughn Member of Mowry Shale (East) and of Blackleaf Formation (West)},
  author = {R. G. Tysdal and T. S. Dyman and D. J. Nichols},
  year = {1989},
  url = {https://pubs.usgs.gov/publication/70015897},
  note = {Source identifier: 70015897}
}