@misc{indiciae71efad4136ea,
  title = {Digital grid of isostatic residual gravity of North America; a digital database},
  author = {Robert W. Simpson and Robert C. Jachens},
  year = {1995},
  doi = {10.3133/ofr95238},
  url = {https://pubs.usgs.gov/publication/ofr95238},
  note = {Source identifier: ofr95238}
}