@misc{indiciaed8196618959a,
  title = {Description and identification of American Black Duck, Mallard, and hybrid wing plumage},
  author = {Ronald E. Kirby and Austin Reed and Pierre Dupuis and Holliday H. Obrecht and Walter J. Quist},
  year = {2000},
  url = {https://pubs.usgs.gov/publication/bsr20000002},
  note = {Source identifier: bsr20000002}
}