@misc{indiciae81bfea185168,
  title = {Some engineering geology problems at Mammoth Cave National Park, Kentucky},
  author = {Frank W. Osterwald},
  year = {1967},
  doi = {10.3133/ofr67173},
  url = {https://pubs.usgs.gov/publication/ofr67173},
  note = {Source identifier: ofr67173}
}