@misc{indiciae87c7571f39bd,
  title = {Graphite deposits near Sturbridge, Massachusetts},
  author = {Earl T. Apfel},
  year = {1945},
  doi = {10.3133/ofr4563},
  url = {https://pubs.usgs.gov/publication/ofr4563},
  note = {Source identifier: ofr4563}
}