TY  - RPRT
TI  - Average elevation map of the conterminous United States (Gilluly averaging method)
AU  - W.H. Diment
AU  - T. C. Urban
PY  - 1981
DO  - 10.3133/gp933
UR  - https://pubs.usgs.gov/publication/gp933
ID  - gp933
ER  -