@misc{indiciae75c3b981ebdf,
  title = {Preservation of cycad and Ginkgo pollen},
  author = {N. O. Frederiksen},
  year = {1978},
  doi = {10.1016/0034-6667(78)90036-2},
  url = {https://pubs.usgs.gov/publication/70010378},
  note = {Source identifier: 70010378}
}