@misc{indiciae37336de89d88,
  title = {Geochemical prospecting for zinc, lead, copper, and silver, Lancaster Valley, southeastern Pennsylvania},
  author = {Jacob Freedman},
  year = {1968},
  doi = {10.3133/ofr68106},
  url = {https://pubs.usgs.gov/publication/ofr68106},
  note = {Source identifier: ofr68106}
}