@misc{indiciaec3c59e0894ba,
  title = {Map showing thickness of principal clay unit, Manchester Quadrangle, Connecticut},
  author = {W. H. Langer},
  year = {1973},
  doi = {10.3133/mf452d},
  url = {https://pubs.usgs.gov/publication/mf452D},
  note = {Source identifier: mf452D}
}