@misc{indiciae8bd26adb3d17,
  title = {Map showing slate quarries and dumps in the Stroudsburg quadrangle, Pennsylvania-New Jersey, with a discussion of their environmental significance},
  author = {J. B. Epstein},
  year = {1974},
  doi = {10.3133/mf578a},
  url = {https://pubs.usgs.gov/publication/mf578A},
  note = {Source identifier: mf578A}
}