@misc{indiciaeeda0fd9de47a,
  title = {Geology of pre-Tertiary rocks in the northern part of Yellowstone National Park, Wyoming},
  author = {E. T. Ruppel},
  year = {1972},
  doi = {10.3133/pp729a},
  url = {https://pubs.usgs.gov/publication/pp729A},
  note = {Source identifier: pp729A}
}