@misc{indiciaef616c7e7a8b1,
  title = {Statistical analysis of surface-water-quality data in and near the coal-mining region of southwestern Indiana, 1957-80},
  author = {Jeffrey D. Martin and Charles G. Crawford},
  year = {1987},
  doi = {10.3133/wsp2291},
  url = {https://pubs.usgs.gov/publication/wsp2291},
  note = {Source identifier: wsp2291}
}