@misc{indiciae12abc460928b,
  title = {Gypsum in the southern part of the Bighorn Mountains, Wyoming},
  author = {C. T. Lupton and D. D. Condit},
  year = {1917},
  doi = {10.3133/b640h},
  url = {https://pubs.usgs.gov/publication/b640H},
  note = {Source identifier: b640H}
}