@misc{indiciae426b0ac1fa5e,
  title = {Spectrographic analyses of insoluble-residue samples, Joplin 1 degree x 2 degrees quadrangle, Kansas and Missouri; drill hole Nos. 7, 8, and 9},
  author = {John H. Bullock and Helen A. Whitney},
  year = {1989},
  doi = {10.3133/ofr89120},
  url = {https://pubs.usgs.gov/publication/ofr89120},
  note = {Source identifier: ofr89120}
}