@misc{indiciae9a7cc2b2703a,
  title = {Results of spirit leveling in Minnesota 1897 to 1910, inclusive},
  author = {Robert Bradford Marshall},
  year = {1911},
  doi = {10.3133/b453},
  url = {https://pubs.usgs.gov/publication/b453},
  note = {Source identifier: b453}
}