@misc{indiciae38a5bf6141cc,
  title = {Twenty-first annual report of the Director of the United States Geological Survey, 1899-1900: Part I - Director's report, including triangulation, primary traverse, and spirit leveling},
  author = {Charles D. Walcott},
  year = {1900},
  doi = {10.3133/ar21\_1},
  url = {https://pubs.usgs.gov/publication/ar21\_1},
  note = {Source identifier: ar21\_1}
}