@misc{indiciae818fcb7ebdec,
  title = {Preliminary bedrock geologic map of the Marlborough quadrangle, Middlesex and Worcester Counties, Massachusetts},
  author = {J. Christopher Hepburn and Richard G. DiNitto},
  year = {1978},
  doi = {10.3133/ofr78222},
  url = {https://pubs.usgs.gov/publication/ofr78222},
  note = {Source identifier: ofr78222}
}