@misc{indiciaed714f0394481,
  title = {Aeromagnetic map of the Mount Grace quadrangle and part of the Northfield quadrangle, Franklin and Worcester Counties, Massachusetts, and Cheshire County, New Hampshire},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1971},
  doi = {10.3133/gp726},
  url = {https://pubs.usgs.gov/publication/gp726},
  note = {Source identifier: gp726}
}