@misc{indiciae20acba2c0c3b,
  title = {Bedrock outcrops and areas of thin drift; areas underlain by sedimentary rocks and areas underlain by igneous and metamorphic rocks also shown; Ellington Quadrangle, Connecticut},
  author = {R. B. Colton},
  year = {1972},
  doi = {10.3133/ofr7274},
  url = {https://pubs.usgs.gov/publication/ofr7274},
  note = {Source identifier: ofr7274}
}