@misc{indiciae03c87d85ab46,
  title = {Distance estimation as a variable in estimating bird numbers from vocalizations},
  author = {J. M. Scott and F. L. Ramsey and C. B. Kepler},
  year = {1981},
  url = {https://pubs.usgs.gov/publication/5210254},
  note = {Source identifier: 5210254}
}