@misc{indiciae63997e024420,
  title = {Defining the Devonian: 1979-89},
  author = {W. A. Oliver and I. Chlupac},
  year = {1991},
  doi = {10.1111/j.1502-3931.1991.tb01185.x},
  url = {https://pubs.usgs.gov/publication/70016613},
  note = {Source identifier: 70016613}
}