@misc{indiciae3d2d37026273,
  title = {Background material for integrated marine navigation systems, marine gravimeters, and magnetometers/gradiometers},
  author = {Robert Brune},
  year = {1977},
  doi = {10.3133/ofr77648},
  url = {https://pubs.usgs.gov/publication/ofr77648},
  note = {Source identifier: ofr77648}
}