@misc{indiciae13421dcb2c5e,
  title = {Preliminary map showing sand and gravel deposits of South Dakota},
  author = {D. M. Larrabee},
  year = {1946},
  doi = {10.3133/mb4},
  url = {https://pubs.usgs.gov/publication/mb4},
  note = {Source identifier: mb4}
}