@misc{indiciae474ec33f1289,
  title = {Results of spirit leveling in Maryland, 1896 to 1911, inclusive},
  author = {Robert Bradford Marshall},
  year = {1914},
  doi = {10.3133/b563},
  url = {https://pubs.usgs.gov/publication/b563},
  note = {Source identifier: b563}
}