@misc{indiciae9892aa8a1cbe,
  title = {Bibliography of North American geology, 1929 and 1930},
  author = {John M. Nickles},
  year = {1931},
  doi = {10.3133/b834},
  url = {https://pubs.usgs.gov/publication/b834},
  note = {Source identifier: b834}
}