@misc{indiciae2cf0390852f9,
  title = {Geology and mineral resources of the Quakertown-Doylestown district, Pennsylvania and New Jersey},
  author = {Florence Bascom and Edgar Theodore Wherry and George W. Stose and A. I. Jonas},
  year = {1931},
  doi = {10.3133/b828},
  url = {https://pubs.usgs.gov/publication/b828},
  note = {Source identifier: b828}
}