@misc{indiciae78fe1b13b4af,
  title = {Elevation-relief ratio, hypsometric integral, and geomorphic area-altitude analysis.},
  author = {Pike, R. J. and Wilson, S. E.},
  year = {1971},
  url = {https://ntrs.nasa.gov/citations/19720032373},
  note = {Source identifier: 19720032373}
}