@misc{indiciae1f29e23dc9b8,
  title = {Overview of national bird population monitoring programs and databases},
  author = {G.S. Butcher and B. Peterjohn and C.J. Ralph},
  year = {1993},
  url = {https://pubs.usgs.gov/publication/5210853},
  note = {Source identifier: 5210853}
}