@misc{indiciae046cfb6be7c8,
  title = {Mineral resources of the Gunnison Gorge Wilderness Study Area, Montrose and Delta counties, Colorado},
  author = {Theodore J. Armbrustmacher and H. N. Barton and D. M. Kulik and Keenan Lee and S. Don Brown},
  year = {1989},
  doi = {10.3133/b1715d},
  url = {https://pubs.usgs.gov/publication/b1715D},
  note = {Source identifier: b1715D}
}