@misc{indiciae05274c51fe08,
  title = {Map showing location of sand, gravel, and till pits in Ellington quadrangle, Connecticut},
  author = {Roger B. Colton and Michael J. Mallory},
  year = {1968},
  doi = {10.3133/ofr6956},
  url = {https://pubs.usgs.gov/publication/ofr6956},
  note = {Source identifier: ofr6956}
}