@misc{indiciaeaab0119ef657,
  title = {Map showing total intensity geomagnetic field of the Caribbean region},
  author = {J.E. Matthews},
  year = {1976},
  doi = {10.3133/mf742},
  url = {https://pubs.usgs.gov/publication/mf742},
  note = {Source identifier: mf742}
}