@misc{indiciae03127d3aec72,
  title = {A model of the productivity of the mallard duck},
  author = {Douglas H. Johnson and Donald W. Sparling and Lewis M. Cowardin},
  year = {1987},
  doi = {10.1016/0304-3800(87)90100-1},
  url = {https://pubs.usgs.gov/publication/1001541},
  note = {Source identifier: 1001541}
}