TY  - RPRT
TI  - Elevation-relief ratio, hypsometric integral, and geomorphic area-altitude analysis
AU  - Richard J. Pike
AU  - Stephen E. Wilson
PY  - 1971
DO  - 10.1130/0016-7606(1971)82[1079:erhiag]2.0.co;2
UR  - https://pubs.usgs.gov/publication/70227441
ID  - 70227441
ER  -