TY  - RPRT
TI  - Preliminary reports and maps released by Geological Survey
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1947
DO  - 10.3133/ofr4728
UR  - https://pubs.usgs.gov/publication/ofr4728
ID  - ofr4728
ER  -