@misc{indiciae4255a76cbaae,
  title = {Aeromagnetic map of the Shirley quadrangle, Worcester and Middlesex Counties, Massachusetts},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1971},
  doi = {10.3133/gp740},
  url = {https://pubs.usgs.gov/publication/gp740},
  note = {Source identifier: gp740}
}