@misc{indiciae454cd2e81ee4,
  title = {Epigenetic sulfide mineralization associated with Pennsylvanian paleokarst in eastern Iowa, U.S.A.},
  author = {P.L. Garvin and Greg A. Ludvigson},
  year = {1993},
  doi = {10.1016/0009-2541(93)90131-2},
  url = {https://pubs.usgs.gov/publication/70018236},
  note = {Source identifier: 70018236}
}