@misc{indiciae1e4192983ff7,
  title = {Evaluation of bursal depth as an indicator of age class of harlequin ducks},
  author = {D.D. Mather and Daniel Esler},
  year = {1999},
  url = {https://pubs.usgs.gov/publication/70021868},
  note = {Source identifier: 70021868}
}