@misc{indiciaeefda9decffeb,
  title = {Subspecific identification of song sparrows collected at Raleigh, N.C.,in summer of 1967},
  author = {P.W. Sykes and R.C. Laybourne},
  year = {1974},
  url = {https://pubs.usgs.gov/publication/5221043},
  note = {Source identifier: 5221043}
}