@misc{indiciae0eb1eec391cd,
  title = {Results of spirit leveling in Michigan and Wisconsin 1897 to 1909, inclusive},
  author = {Robert Bradford Marshall},
  year = {1911},
  doi = {10.3133/b461},
  url = {https://pubs.usgs.gov/publication/b461},
  note = {Source identifier: b461}
}