@misc{indiciaec3d97b769efe,
  title = {Population trends of the Purple Martin in North America, 1966-1986},
  author = {J.R. Sauer and M. K. Klimkiewicz and Sam Droege},
  year = {1988},
  url = {https://pubs.usgs.gov/publication/5224797},
  note = {Source identifier: 5224797}
}