@misc{indiciaef1e6e100ffd4,
  title = {Operator's manual on the visual-accumulation tube method for sedimentation analysis of sands},
  author = {V.C. Colby and F.W. Witzgman},
  year = {1958},
  url = {https://pubs.usgs.gov/publication/70170553},
  note = {Source identifier: 70170553}
}