@misc{indiciae01774364091c,
  title = {Preliminary reconnaissance map showing landslides in Butler County, Pennsylvania},
  author = {John S. Pomeroy},
  year = {1977},
  doi = {10.3133/ofr77246},
  url = {https://pubs.usgs.gov/publication/ofr77246},
  note = {Source identifier: ofr77246}
}