@misc{indiciae21310e10a1a5,
  title = {Spirit leveling in Kentucky, 1914 to 1916, inclusive},
  author = {Robert Bradford Marshall},
  year = {1918},
  doi = {10.3133/b673},
  url = {https://pubs.usgs.gov/publication/b673},
  note = {Source identifier: b673}
}