@misc{indiciaea42fbd41b031,
  title = {Aeromagnetic map of the Lawrence quadrangle, Essex and Middlesex Counties, Massachusetts, and Rockingham and Hillsborough Counties, New Hampshire},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1970},
  doi = {10.3133/gp716},
  url = {https://pubs.usgs.gov/publication/gp716},
  note = {Source identifier: gp716}
}