@misc{indiciae24e4debdb6f9,
  title = {Trace metal records of regional paleoenvironmental variability in Pennsylvanian (Upper Carboniferous) black shales},
  author = {A.M. Cruse and T.W. Lyons},
  year = {2004},
  doi = {10.1016/j.chemgeo.2003.12.010},
  url = {https://pubs.usgs.gov/publication/70027047},
  note = {Source identifier: 70027047}
}