@misc{indiciae12c8467c6d97,
  title = {Digital colored Bouguer gravity, free-air gravity, station location, and terrain maps for the conterminous United States},
  author = {R.W. Simpson and T.G. Hildenbrand and R. H. Godson and M. F. Kane},
  year = {1987},
  doi = {10.3133/gp953b},
  url = {https://pubs.usgs.gov/publication/gp953B},
  note = {Source identifier: gp953B}
}