@misc{indiciaee7ed6ec1809c,
  title = {Aeromagnetic map of the Blackstone Quadrangle, Worcester County, Massachusetts, and Providence County, Rhode Island},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1971},
  doi = {10.3133/gp770},
  url = {https://pubs.usgs.gov/publication/gp770},
  note = {Source identifier: gp770}
}