@misc{indiciae47a714ab1c67,
  title = {Preliminary map showing construction materials in the south one-half of Williams County, North Dakota},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1947},
  doi = {10.3133/ofr4722},
  url = {https://pubs.usgs.gov/publication/ofr4722},
  note = {Source identifier: ofr4722}
}