@misc{indiciae1be16cca03fd,
  title = {Map showing depth to bedrock, Mount Tom quadrangle, Massachusetts},
  author = {C.J. Londquist and F. D. Larsen},
  year = {1976},
  doi = {10.3133/mf504c},
  url = {https://pubs.usgs.gov/publication/mf504C},
  note = {Source identifier: mf504C}
}