@misc{indiciae02b094324f14,
  title = {The roughness of natural terrain: A planetary and remote sensing perspective},
  author = {Michael K. Shepard and Bruce A. Campbell and Mark H. Bulmer and Lisa R. Gaddis and Tom G. Farr and Jeffrey J. Plaut},
  year = {2001},
  doi = {10.1029/2000je001429},
  url = {https://pubs.usgs.gov/publication/70023143},
  note = {Source identifier: 70023143}
}