@misc{indiciaebd0cb2f83ca7,
  title = {Water-resources activities of the U.S. Geological Survey in Pennsylvania, 1988-89},
  author = {Robert E. Helm},
  year = {1989},
  doi = {10.3133/ofr89273},
  url = {https://pubs.usgs.gov/publication/ofr89273},
  note = {Source identifier: ofr89273}
}