@misc{indiciaee27b1a207a47,
  title = {Frequency curves},
  author = {H. C. Riggs},
  year = {1968},
  doi = {10.3133/twri04a2},
  url = {https://pubs.usgs.gov/publication/twri04A2},
  note = {Source identifier: twri04A2}
}