@misc{indiciaecc566d46b814,
  title = {Bedrock contour maps of the Lower Great Miami River valley, Ohio},
  author = {A. M. Spieker and J. S. Watkins},
  year = {1967},
  doi = {10.3133/ofr67205},
  url = {https://pubs.usgs.gov/publication/ofr67205},
  note = {Source identifier: ofr67205}
}