@misc{indiciae654e1889e599,
  title = {Arsenic and lead concentrations in the Pond Creek and Fire Clay coal beds, eastern Kentucky coal field},
  author = {J.C. Hower and J.D. Robertson and A.S. Wong and C.F. Eble and L.F. Ruppert},
  year = {1997},
  doi = {10.1016/s0883-2927(96)00071-6},
  url = {https://pubs.usgs.gov/publication/70019737},
  note = {Source identifier: 70019737}
}