@misc{indiciae7fca6b6ae91c,
  title = {Surficial geologic map of the Hampden quadrangle, Massachusetts-Connecticut},
  author = {Roger B. Colton},
  year = {1971},
  doi = {10.3133/ofr7173},
  url = {https://pubs.usgs.gov/publication/ofr7173},
  note = {Source identifier: ofr7173}
}