@misc{indiciae70f56a8ba90a,
  title = {Population ecology of the mallard: IV. A review of duck hunting regulations, activity, and success, with special reference to the mallard},
  author = {Elwood M. Martin and Samuel M. Carney},
  year = {1977},
  url = {https://pubs.usgs.gov/publication/rp130},
  note = {Source identifier: rp130}
}