@misc{indiciae21f20e91c5dd,
  title = {Gravity observations in Northwest Costa Rica},
  author = {D. A. Ponce},
  year = {1986},
  doi = {10.3133/ofr86556},
  url = {https://pubs.usgs.gov/publication/ofr86556},
  note = {Source identifier: ofr86556}
}