@misc{indiciae74bc11c8982f,
  title = {An automatic camera device for measuring waterfowl use},
  author = {Lewis M. Cowardin and J.E. Ashe},
  year = {1965},
  doi = {10.2307/3798066},
  url = {https://pubs.usgs.gov/publication/1001418},
  note = {Source identifier: 1001418}
}