@misc{indiciae2206b88bd011,
  title = {Bedrock geologic map of the Egremont Quadrangle and adjacent areas, Berkshire County, Massachusetts, and Columbia County, New York},
  author = {E-an Zen and N. M. Ratcliffe},
  year = {1971},
  doi = {10.3133/i628},
  url = {https://pubs.usgs.gov/publication/i628},
  note = {Source identifier: i628}
}