@misc{indiciaef04e6cdb20da,
  title = {Geology of the Dubuque North quadrangle, Iowa-Wisconsin-Illinois},
  author = {Jesse W. Whitlow and C. Ervin Brown},
  year = {1963},
  doi = {10.3133/b1123c},
  url = {https://pubs.usgs.gov/publication/b1123C},
  note = {Source identifier: b1123C}
}