@misc{indiciaec8e4e67020df,
  title = {Spirit leveling in South Dakota 1896 to 1915, inclusive},
  author = {Robert Bradford Marshall},
  year = {1916},
  doi = {10.3133/b643},
  url = {https://pubs.usgs.gov/publication/b643},
  note = {Source identifier: b643}
}