@misc{indiciae66d19b8c6c52,
  title = {Preliminary map showing the thickness and character of Quaternary sediments in the United States east of the Rocky Mountains},
  author = {D. R. Soller},
  year = {1993},
  doi = {10.3133/ofr93543},
  url = {https://pubs.usgs.gov/publication/ofr93543},
  note = {Source identifier: ofr93543}
}