@misc{indiciae4dae5da28901,
  title = {Plotting programs for rare earth elements, spider diagrams, and ternary diagrams},
  author = {P. E. Bruggman},
  year = {1988},
  doi = {10.3133/ofr889},
  url = {https://pubs.usgs.gov/publication/ofr889},
  note = {Source identifier: ofr889}
}