TY  - RPRT
TI  - 1:2,000,000-scale digital line graph (DLG) data
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1992
DO  - 10.3133/ds4
UR  - https://pubs.usgs.gov/publication/ds4
ID  - ds4
ER  -