@misc{indiciae1acba039f074,
  title = {Magnetic horizontal intensity in the United States; epoch 1975.0},
  author = {E.B. Fabiano and W. J. Jones},
  year = {1976},
  doi = {10.3133/i913},
  url = {https://pubs.usgs.gov/publication/i913},
  note = {Source identifier: i913}
}