@misc{indiciae2081b142a79d,
  title = {Contour map of the bedrock surface, Mount Tom Quadrangle, Massachusetts},
  author = {C.J. Londquist},
  year = {1973},
  doi = {10.3133/mf504a},
  url = {https://pubs.usgs.gov/publication/mf504A},
  note = {Source identifier: mf504A}
}