@misc{indiciaefeb0d9e79a77,
  title = {Results of spirit leveling in Kentucky, 1898 to 1913, inclusive},
  author = {Robert Bradford Marshall},
  year = {1914},
  doi = {10.3133/b554},
  url = {https://pubs.usgs.gov/publication/b554},
  note = {Source identifier: b554}
}