@misc{indiciaeaadaa1910e44,
  title = {Principal facts for gravity stations in the Ajo 1 degree x 2 degrees Quadrangle and the Papago Indian Reservation, Southwest Arizona},
  author = {Frances M. Boler and M. Baer},
  year = {1981},
  doi = {10.3133/ofr81993},
  url = {https://pubs.usgs.gov/publication/ofr81993},
  note = {Source identifier: ofr81993}
}