@misc{indiciaea580cb85e90e,
  title = {An attempt to freeze-brand mallard ducklings},
  author = {R. J. Greenwood},
  year = {1975},
  doi = {10.2307/4512135},
  url = {https://pubs.usgs.gov/publication/1001599},
  note = {Source identifier: 1001599}
}