@misc{indiciaedef23c5e4806,
  title = {Spirit leveling in Louisiana, 1903 to 1915, inclusive},
  author = {Robert Bradford Marshall},
  year = {1916},
  doi = {10.3133/b634},
  url = {https://pubs.usgs.gov/publication/b634},
  note = {Source identifier: b634}
}