@misc{indiciaeb4a2ba25c4ef,
  title = {Aeromagnetic map of part of the Salem Depot quadrangle, Rockingham County, New Hampshire and Essex County, Massachusetts},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1970},
  doi = {10.3133/gp712},
  url = {https://pubs.usgs.gov/publication/gp712},
  note = {Source identifier: gp712}
}