TY  - RPRT
TI  - Geologic map and digital database of the Porcupine Wash 7.5 minute Quadrangle, Riverside County, southern California
AU  - Robert E. Powell
PY  - 2001
DO  - 10.3133/ofr0130
UR  - https://pubs.usgs.gov/publication/ofr0130
ID  - ofr0130
ER  -