@misc{indiciae48aae94235df,
  title = {Tree rings : timekeepers of the past},
  author = {Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey},
  year = {1973},
  doi = {10.3133/7000082},
  url = {https://pubs.usgs.gov/publication/7000082},
  note = {Source identifier: 7000082}
}