@misc{indiciae7491c6509123,
  title = {Preliminary geologic map of the northwest part of the Burdock quadrangle, Fall River and Custer Counties, South Dakota},
  author = {R. W. Schnabel and L.J. Charlesworth},
  year = {1958},
  doi = {10.3133/mf73},
  url = {https://pubs.usgs.gov/publication/mf73},
  note = {Source identifier: mf73}
}