@misc{indiciaebd0d7d0057be,
  title = {Transcontinental geophysical survey (35°-39° N) magnetic map from 100° to 112° W longitude},
  author = {Isidore Zietz and J.R. Kirby},
  year = {1968},
  doi = {10.3133/i533a},
  url = {https://pubs.usgs.gov/publication/i533A},
  note = {Source identifier: i533A}
}