@misc{indiciaec5e60c805c2e,
  title = {Identifying pondweed seeds eaten by ducks},
  author = {Alexander C. Martin},
  year = {1951},
  doi = {10.2307/3797217},
  url = {https://pubs.usgs.gov/publication/5220454},
  note = {Source identifier: 5220454}
}