@misc{indiciaeceab6142d838,
  title = {Origin and microfossils of the oil shale of the Green River formation of Colorado and Utah},
  author = {W. H. Bradley},
  year = {1931},
  doi = {10.3133/pp168},
  url = {https://pubs.usgs.gov/publication/pp168},
  note = {Source identifier: pp168}
}