@misc{indiciaec510e4e65ec0,
  title = {Fitting curves to cyclic data},
  author = {W. B. Langbein},
  year = {1955},
  doi = {10.3133/ofr5591},
  url = {https://pubs.usgs.gov/publication/ofr5591},
  note = {Source identifier: ofr5591}
}