@misc{indiciaeb95578cae627,
  title = {Isostatic residual gravity, topographic, and first-vertical derivative gravity maps of the conterminous United States},
  author = {R.W. Simpson and R.C. Jachens and R. W. Saltus and R.J. Blakely},
  year = {1986},
  doi = {10.3133/gp975},
  url = {https://pubs.usgs.gov/publication/gp975},
  note = {Source identifier: gp975}
}