@misc{indiciaefbb0ae3d6978,
  title = {Stratigraphic distribution of species of the megaspore genus Minerisporites in North America},
  author = {Robert H. Tschudy},
  year = {1976},
  doi = {10.3133/pp743e},
  url = {https://pubs.usgs.gov/publication/pp743E},
  note = {Source identifier: pp743E}
}