@misc{indiciaea0e435a33267,
  title = {Analytical methods as applied in petrographic investigations of Appalachian Basin},
  author = {Gordon Rittenhouse},
  year = {1948},
  doi = {10.3133/cir22},
  url = {https://pubs.usgs.gov/publication/cir22},
  note = {Source identifier: cir22}
}