@misc{indiciae2e5054b8e8e4,
  title = {Relation of the lower Pennsylvanian unconformity to a mid-carboniferous eustatic event in the eastern United States},
  author = {K. J. Englund and R. E. Thomas},
  year = {1997},
  url = {https://pubs.usgs.gov/publication/70206433},
  note = {Source identifier: 70206433}
}