@misc{indiciae2339d962762a,
  title = {The chromograph, a new analytical tool for laboratory and field use},
  author = {Rollin Elbert Stevens and Hubert William Lakin},
  year = {1949},
  doi = {10.3133/cir63},
  url = {https://pubs.usgs.gov/publication/cir63},
  note = {Source identifier: cir63}
}