@misc{indiciae7f5810b0394b,
  title = {Map showing distribution of alkaline igneous rocks and associated carbonatites and peridotites in the northern Midcontinent, U.S.A.},
  author = {F. A. Hills and R. W. Scott and T.J. Armbrustmacher and Pieter Berendsen},
  year = {1991},
  doi = {10.3133/mf1835f},
  url = {https://pubs.usgs.gov/publication/mf1835F},
  note = {Source identifier: mf1835F}
}