@misc{indiciae3698de5b97b2,
  title = {Thirty-second winter bird-population study. 9a. Upland tulip-tree--maple--oak forest},
  author = {C.S. Robbins},
  year = {1980},
  url = {https://pubs.usgs.gov/publication/5221564},
  note = {Source identifier: 5221564}
}