@misc{indiciae198a68c5ddb2,
  title = {Spectrographic analyses of insoluble-residue samples, Joplin 1 degree x 2 degrees Quadrangle, Missouri and Kansas; drill hole Nos. 119, 120, and 121},
  author = {J. H. Bullock and H. W. Folger},
  year = {1990},
  doi = {10.3133/ofr908},
  url = {https://pubs.usgs.gov/publication/ofr908},
  note = {Source identifier: ofr908}
}