@misc{indiciae579b28ad2d80,
  title = {High-resolution leaf-fossil record spanning the Cretaceous/ Tertiary boundary},
  author = {Kirk R. Johnson and Douglas J. Nichols and M. Attrep and C. J. Orth},
  year = {1989},
  doi = {10.1038/340708a0},
  url = {https://pubs.usgs.gov/publication/70221499},
  note = {Source identifier: 70221499}
}