@misc{indiciae57df316a5f30,
  title = {Carboniferous megafaunal and microfaunal zonation in the northern Cordillera of the United States},
  author = {W.J. Sando and B. L. Mamet and J.T. Dutro},
  year = {1969},
  doi = {10.3133/pp613e},
  url = {https://pubs.usgs.gov/publication/pp613E},
  note = {Source identifier: pp613E}
}