@misc{indiciae1f9a613b7f88,
  title = {Reports and maps of the Geological Survey released only in the open files, 1968},
  author = {Betsy A. Weld and Margaret S. Griffin and George W. Brett},
  year = {1969},
  doi = {10.3133/cir568},
  url = {https://pubs.usgs.gov/publication/cir568},
  note = {Source identifier: cir568}
}