@misc{indiciae20b6641601ff,
  title = {White-crowned sparrows wintering in Maryland and West Virginia},
  author = {L. M. Llewellyn},
  year = {1949},
  doi = {10.2307/4080700},
  url = {https://pubs.usgs.gov/publication/5220497},
  note = {Source identifier: 5220497}
}