@misc{indiciaecdfa761c9609,
  title = {A modification of the U.S. Geological Survey one-sixth order semiquantitative spectrographic method for the analysis of geologic materials that improves limits of determination of some volatile to moderately volatile elements},
  author = {D.E. Detra and Elmo F. Cooley},
  year = {1988},
  doi = {10.3133/cir996},
  url = {https://pubs.usgs.gov/publication/cir996},
  note = {Source identifier: cir996}
}