@misc{indiciaea59be3723fb5,
  title = {Hydrogeology of the Cambrian-Ordovician aquifer system in the northern Midwest, United States with a section on ground-water quality},
  author = {H. L. Young and D. I. Siegel},
  year = {1992},
  doi = {10.3133/pp1405b},
  url = {https://pubs.usgs.gov/publication/pp1405B},
  note = {Source identifier: pp1405B}
}