@misc{indiciae4582931c3ba9,
  title = {Geology and magnetic anomalies of T. 42 N., R. 30 W., Dickinson County, Michigan},
  author = {F.J. Pettijohn},
  year = {1951},
  doi = {10.3133/ofr5176},
  url = {https://pubs.usgs.gov/publication/ofr5176},
  note = {Source identifier: ofr5176}
}