@misc{indiciae16dde3103c1b,
  title = {Triangulation and primary traverse, 1913-1915; R.B. Marshall, Chief Geographer. Primary traverse in Illinois, Wisconsin, Minnesota, North Dakota, and South Dakota, 1913-1915},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1916},
  doi = {10.3133/b644e},
  url = {https://pubs.usgs.gov/publication/b644E},
  note = {Source identifier: b644E}
}