@misc{indiciae60ddb0eda14b,
  title = {Surficial materials in the conterminous United States},
  author = {David R. Soller and Marith C. Reheis},
  year = {2004},
  doi = {10.3133/ofr2003275},
  url = {https://pubs.usgs.gov/publication/ofr2003275},
  note = {Source identifier: ofr2003275}
}