@misc{indiciaed1ec66f62558,
  title = {Locating waterfowl observations on aerial surveys},
  author = {W.I. Butler and J.I. Hodges and R.A. Stehn},
  year = {1995},
  url = {https://pubs.usgs.gov/publication/1013313},
  note = {Source identifier: 1013313}
}