@misc{indiciae9fcb5820abc6,
  title = {Underwater observations of breakwaters at North Point Marina, Winthrop Harbor, Illinois},
  author = {R.C. Circe and D. Blackwood},
  year = {1991},
  doi = {10.3133/ofr91327},
  url = {https://pubs.usgs.gov/publication/ofr91327},
  note = {Source identifier: ofr91327}
}