@misc{indiciae6c0cf24a11d0,
  title = {A preliminary report on the bentonite beds of the lower Virgin Creek Member of the Pierre Shale, Stanley County, South Dakota ( USA).},
  author = {D. S. Collins},
  year = {1987},
  url = {https://pubs.usgs.gov/publication/70014673},
  note = {Source identifier: 70014673}
}