@misc{indiciaeafcab68116c7,
  title = {Geologic sketch map of northeastern Massachusetts},
  author = {K.G. Bell and D.C. Alvord},
  year = {1974},
  doi = {10.3133/ofr74356},
  url = {https://pubs.usgs.gov/publication/ofr74356},
  note = {Source identifier: ofr74356}
}