@misc{indiciae1d0ecc92106c,
  title = {Mercury, lead, cadmium, and arsenic residues in starlings--1971},
  author = {William E. Martin and Paul R. Nickerson},
  year = {1973},
  url = {https://pubs.usgs.gov/publication/70210022},
  note = {Source identifier: 70210022}
}