@misc{indiciae6dc885d07f1d,
  title = {Water-resources activities of the U.S. Geological Survey in Pennsylvania, 1986-87},
  author = {R. E. Helm},
  year = {1987},
  doi = {10.3133/ofr87475},
  url = {https://pubs.usgs.gov/publication/ofr87475},
  note = {Source identifier: ofr87475}
}