@misc{indiciae2c9bf161cb20,
  title = {Bouguer gravity map of the Portland 1° x 2° quadrangle, Maine and New Hampshire},
  author = {Wallace A. Bothner and R.W. Simpson and R.P. Kucks},
  year = {1979},
  doi = {10.3133/ofr79872},
  url = {https://pubs.usgs.gov/publication/ofr79872},
  note = {Source identifier: ofr79872}
}