@misc{indiciae009c1055d4f8,
  title = {Spectrographic analyses of insoluble-residue samples, Joplin 1 degree x 2 degrees Quadrangle, Kansas and Missouri; drill hole Nos. 71, 72, 73, and 74},
  author = {J. H. Bullock and H. W. Folger},
  year = {1989},
  doi = {10.3133/ofr89656},
  url = {https://pubs.usgs.gov/publication/ofr89656},
  note = {Source identifier: ofr89656}
}