@misc{indiciaea81be102720a,
  title = {Petrographic differentiation of depositional environments of sandstones of the Pennsylvanian Breathitt Formation, northeastern Kentucky and southwestern West Virginia},
  author = {Romeo M. Flores},
  year = {1978},
  url = {https://pubs.usgs.gov/publication/70156361},
  note = {Source identifier: 70156361}
}