@misc{indiciae111195b1ad2a,
  title = {Geologic maps of anthracite-bearing rocks in the west-central part of the southern anthracite field, Pennsylvania, western area},
  author = {G.H. Wood and J. P. Trexler},
  year = {1968},
  doi = {10.3133/i529},
  url = {https://pubs.usgs.gov/publication/i529},
  note = {Source identifier: i529}
}