@misc{indiciae5f0faa0850d0,
  title = {Gadwall nesting in Maryland},
  author = {P. F. Springer and R. E. Stewart},
  year = {1950},
  doi = {10.2307/4081221},
  url = {https://pubs.usgs.gov/publication/5220164},
  note = {Source identifier: 5220164}
}