@misc{indiciaee04129073bf2,
  title = {Three-dimensional geologic maps of Quaternary sediments in east-central Illinois},
  author = {D. R. Soller and S. D. Price and J. P. Kempton and R. C. Berg},
  year = {1999},
  doi = {10.3133/i2669},
  url = {https://pubs.usgs.gov/publication/i2669},
  note = {Source identifier: i2669}
}