@misc{indiciaeef2bfeed267f,
  title = {Geology and mineral resources of the Middletown quadrangle, Pennsylvania},
  author = {George W. Stose and A. I. Jonas},
  year = {1933},
  doi = {10.3133/b840},
  url = {https://pubs.usgs.gov/publication/b840},
  note = {Source identifier: b840}
}