@misc{indiciae67174e010540,
  title = {Principal facts for 113 gravity stations in the Salton Sea 1 degree x 2 degrees Quadrangle, Southern California},
  author = {M.G. Helferty and C.F. Erdman},
  year = {1985},
  doi = {10.3133/ofr85520},
  url = {https://pubs.usgs.gov/publication/ofr85520},
  note = {Source identifier: ofr85520}
}