@misc{indiciae5a155f43fd0a,
  title = {Map showing depth to bedrock, Mount Holyoke quadrangle, Massachusetts},
  author = {C.J. Londquist},
  year = {1976},
  doi = {10.3133/mf640b},
  url = {https://pubs.usgs.gov/publication/mf640B},
  note = {Source identifier: mf640B}
}