@misc{indiciae300bcebd0a37,
  title = {Lower Jurassic (Pliensbachian and Toarcian) ammonites from eastern Oregon and California},
  author = {R. W. Imlay},
  year = {1968},
  doi = {10.3133/pp593c},
  url = {https://pubs.usgs.gov/publication/pp593C},
  note = {Source identifier: pp593C}
}