TY  - RPRT
TI  - Landforms of the conterminous United States — A digital shaded relief portrayal
AU  - Gail P. Thelin
AU  - Richard J. Pike
PY  - 1991
DO  - 10.3133/i2206
UR  - https://pubs.usgs.gov/publication/i2206
ID  - i2206
ER  -