@misc{indiciaedc3d1afcd348,
  title = {Sea otters, sea urchins, and kelp beds: some questions of scale},
  author = {J. A. Estes and C. Harrold},
  year = {1988},
  url = {https://pubs.usgs.gov/publication/87312},
  note = {Source identifier: 87312}
}