@misc{indiciaee1923c58c7d3,
  title = {Aeromagnetic map of the Boulder batholith area, southwestern Montana},
  author = {R. W. Johnson and J. R. Henderson and N.S. Tyson},
  year = {1965},
  doi = {10.3133/gp538},
  url = {https://pubs.usgs.gov/publication/gp538},
  note = {Source identifier: gp538}
}