@misc{indiciaecaa0c338840a,
  title = {Evaluation of an aerial survey of Pacific walruses},
  author = {J. A. Estes and James R. Gilbert},
  year = {1978},
  doi = {10.1139/f78-178},
  url = {https://pubs.usgs.gov/publication/1007802},
  note = {Source identifier: 1007802}
}