@misc{indiciae129e61b634ac,
  title = {Rapid analysis of silicate rocks},
  author = {Leonard Shapiro and Walter Wallace Brannock},
  year = {1956},
  doi = {10.3133/b1036c},
  url = {https://pubs.usgs.gov/publication/b1036C},
  note = {Source identifier: b1036C}
}