@misc{indiciae2a9781754fb0,
  title = {Geologic map and distribution of heavy minerals in Tertiary rocks of the Sheridan 30' x 60' Quadrangle, Wyoming and Montana},
  author = {N.M. Denson and D. L. Macke and R.R. Schumann and M.E. Durrett},
  year = {1990},
  doi = {10.3133/i2020},
  url = {https://pubs.usgs.gov/publication/i2020},
  note = {Source identifier: i2020}
}