@misc{indiciaeaf28e0a6ae08,
  title = {The Chinle (Upper Triassic) and Sundance (Upper Jurassic) Formations in north-central Colorado},
  author = {G. N. Pipiringos and W. J. Hail and G. A. Izett},
  year = {1969},
  doi = {10.3133/b1274n},
  url = {https://pubs.usgs.gov/publication/b1274N},
  note = {Source identifier: b1274N}
}