@misc{indiciae216c36067e6e,
  title = {Spectrographic analyses of insoluble-residue samples, Harrison 1 degree x 2 degrees Quadrangle, Missouri and Arkansas; drill holes nos. 7, 9, and 10},
  author = {M. S. Erickson and Barbara Chazin},
  year = {1987},
  doi = {10.3133/ofr87521},
  url = {https://pubs.usgs.gov/publication/ofr87521},
  note = {Source identifier: ofr87521}
}