@misc{indiciae3349cd4b5b66,
  title = {Pegmatites of Massachusetts, progress report for work done in the summer of 1942},
  author = {M.P. Billings},
  year = {1945},
  doi = {10.3133/ofr4585},
  url = {https://pubs.usgs.gov/publication/ofr4585},
  note = {Source identifier: ofr4585}
}