@misc{indiciae9993968f206d,
  title = {Thirty-first annual report of the Director of the United States Geological Survey},
  author = {George Otis Smith},
  year = {1910},
  doi = {10.3133/ar31},
  url = {https://pubs.usgs.gov/publication/ar31},
  note = {Source identifier: ar31}
}