@misc{indiciae91def984ccaf,
  title = {Taxonomic revision of the Spermatopsida of the Oligocene Creede flora, southern Colorado},
  author = {Howard E. Schorn and Jack A. Wolfe},
  year = {1989},
  doi = {10.3133/ofr89433},
  url = {https://pubs.usgs.gov/publication/ofr89433},
  note = {Source identifier: ofr89433}
}