@misc{indiciae9f2fcecef208,
  title = {Archaeocycas and Phasmatocycas - new genera of Permian cycads},
  author = {Sergius H. Mamay},
  year = {1973},
  url = {https://pubs.usgs.gov/publication/70162011},
  note = {Source identifier: 70162011}
}