@misc{indiciae7d190a85a8f5,
  title = {Spirit leveling in Illinois, 1896-1942. Part 2, West-central Illinois},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1942},
  doi = {10.3133/b930b},
  url = {https://pubs.usgs.gov/publication/b930B},
  note = {Source identifier: b930B}
}