@misc{indiciae282bb00eed84,
  title = {The physical conditions indicated by the flora of the Calvert formation},
  author = {Edward Wilber Berry},
  year = {1917},
  doi = {10.3133/pp98f},
  url = {https://pubs.usgs.gov/publication/pp98F},
  note = {Source identifier: pp98F}
}