@misc{indiciae5f2704c2a3f3,
  title = {Map showing thickness of principal clay unit, Broad Brook quadrangle, Connecticut},
  author = {W. H. Langer},
  year = {1973},
  doi = {10.3133/mf451c},
  url = {https://pubs.usgs.gov/publication/mf451C},
  note = {Source identifier: mf451C}
}