@misc{indiciae9e11c852cdfd,
  title = {Geologic map of the south half of the Shamokin Quadrangle, Northumberland and Columbia counties, Pennsylvania},
  author = {H. H. Arndt and G.H. Wood and R.F. Schryver},
  year = {1973},
  doi = {10.3133/i734},
  url = {https://pubs.usgs.gov/publication/i734},
  note = {Source identifier: i734}
}