@misc{indiciaee0c07a8539da,
  title = {U-Pb age of zircon crystals from the upper banner tonstein (Middle Pennsylvanian), Virginia: Absolute age of the Lower Pennsylvanian-Middle Pennsylvanian boundary and depositional rates for the Middle Pennsylvanian, central appalachian basin},
  author = {P.C. Lyons and T.E. Krogh and Y.Y. Kwok and E.L. Zodrow},
  year = {1997},
  url = {https://pubs.usgs.gov/publication/70019147},
  note = {Source identifier: 70019147}
}