@misc{indiciae6d01ef811d71,
  title = {Observer differences in the North American Breeding Bird Survey},
  author = {J.R. Sauer and B.G. Peterjohn and W.A. Link},
  year = {1994},
  doi = {10.2307/4088504},
  url = {https://pubs.usgs.gov/publication/5222733},
  note = {Source identifier: 5222733}
}