TY  - RPRT
TI  - Geologic map of the Grand Canyon 30' x 60' quadrangle, Coconino and Mohave Counties, northwestern Arizona
AU  - G. H. Billingsley
PY  - 2000
DO  - 10.3133/i2688
UR  - https://pubs.usgs.gov/publication/i2688
ID  - i2688
ER  -