TY  - RPRT
TI  - Secrets in Stone
AU  - David Donnenfield Productions
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1998
DO  - 10.3133/ofr9827
UR  - https://pubs.usgs.gov/publication/ofr9827
ID  - ofr9827
ER  -