@misc{indiciaef99471a9f540,
  title = {Altered tuffaceous rocks of the Green River Formation in the Piceance Creek Basin, Colorado},
  author = {Roy Lee Griggs},
  year = {1968},
  doi = {10.3133/ofr68113},
  url = {https://pubs.usgs.gov/publication/ofr68113},
  note = {Source identifier: ofr68113}
}