@misc{indiciaed4d5ef02df92,
  title = {Map showing thickness of principal clay unit, Glastonbury Quadrangle, Connecticut},
  author = {W. H. Langer},
  year = {1974},
  doi = {10.3133/mf561a},
  url = {https://pubs.usgs.gov/publication/mf561A},
  note = {Source identifier: mf561A}
}