@misc{indiciae6aa7dec43ed7,
  title = {Middle and Upper Ordovician symmetrical univalved mollusks (Monoplacophora and Bellerophontina) of the Cincinnati Arch region},
  author = {G.P. Wahlman},
  year = {1992},
  doi = {10.3133/pp1066o},
  url = {https://pubs.usgs.gov/publication/pp1066O},
  note = {Source identifier: pp1066O}
}