@misc{indiciae48cb71fd3fd8,
  title = {Las Animas Formation (upper Precambrian) in the subsurface of southeastern Colorado},
  author = {Ogden Tweto},
  year = {1983},
  doi = {10.3133/b1529g},
  url = {https://pubs.usgs.gov/publication/b1529G},
  note = {Source identifier: b1529G}
}