@misc{indiciae92b9a39501cb,
  title = {Detection ratios on winter surveys of Rocky Mountain Trumpeter Swans Cygnus buccinator},
  author = {J. Bart and C.D. Mitchell and M.N. Fisher and J.A. Dubovsky},
  year = {2007},
  url = {https://pubs.usgs.gov/publication/70031368},
  note = {Source identifier: 70031368}
}