@misc{indiciae6c9c1d9cf3a7,
  title = {Preliminary bedrock geologic map of the International Falls 1 degree x 2 degree Quadrangle, Minnesota, U.S.A., and Ontario, Canada},
  author = {Warren C. Day and D. L. Southwick and K. J. Schulz and T. L. Klein},
  year = {1987},
  doi = {10.3133/ofr87594},
  url = {https://pubs.usgs.gov/publication/ofr87594},
  note = {Source identifier: ofr87594}
}