@misc{indiciae9dde93418a4e,
  title = {Floral-faunal associations in American coal balls},
  author = {S.H. Mamay and E. L. Yochelson},
  year = {1953},
  doi = {10.1126/science.118.3061.240},
  url = {https://pubs.usgs.gov/publication/70011090},
  note = {Source identifier: 70011090}
}