@misc{indiciaedcbb2e7d991f,
  title = {Sonic depth sounder for laboratory and field use},
  author = {E.V. Richardson and Daryl B. Simons and G.J. Posakony},
  year = {1961},
  doi = {10.3133/cir450},
  url = {https://pubs.usgs.gov/publication/cir450},
  note = {Source identifier: cir450}
}