@misc{indiciae27ce4ee2758e,
  title = {GIS for mapping waterfowl density and distribution from aerial surveys},
  author = {W.I. Butler and R.A. Stehn and G.R. Balogh},
  year = {1995},
  url = {https://pubs.usgs.gov/publication/1013312},
  note = {Source identifier: 1013312}
}