@misc{indiciaecb651d8650c9,
  title = {Contour map of the bedrock surface, Mount Toby Quadrangle, Massachusetts},
  author = {C.J. Londquist},
  year = {1974},
  doi = {10.3133/mf621a},
  url = {https://pubs.usgs.gov/publication/mf621A},
  note = {Source identifier: mf621A}
}