TY  - RPRT
TI  - Physiographic rim of the Grand Canyon, Arizona: A digital database
AU  - George H. Billingsley
AU  - Haydee M. Hampton
PY  - 1999
DO  - 10.3133/ofr9930
UR  - https://pubs.usgs.gov/publication/ofr9930
ID  - ofr9930
ER  -