@misc{indiciaee7136d8bf90a,
  title = {Groundwater flow and velocity in a 500 ka pre-Illinoian till, eastern Iowa},
  author = {K. E. Schilling and S. Tassier-Surine},
  year = {2006},
  doi = {10.1007/s00254-006-0299-9},
  url = {https://pubs.usgs.gov/publication/70028268},
  note = {Source identifier: 70028268}
}