@misc{indiciaee192ff4cdc06,
  title = {Transcontinental geophysical survey (35°–39° N) magnetic map from 112° W longitude to the coast of California},
  author = {Isidore Zietz and J.R. Kirby},
  year = {1968},
  doi = {10.3133/i532a},
  url = {https://pubs.usgs.gov/publication/i532A},
  note = {Source identifier: i532A}
}