@misc{indiciae7123ddb6328b,
  title = {Investigation of bedrock depths by electrical-resistivity methods in the Ripon-Fond du Lac area, Wisconsin},
  author = {H. Cecil Spicer},
  year = {1950},
  doi = {10.3133/cir69},
  url = {https://pubs.usgs.gov/publication/cir69},
  note = {Source identifier: cir69}
}