TY  - RPRT
TI  - Map showing total thickness of Mississippian rocks in the conterminous United States
AU  - Members of the Engineering Geology and Ground Water Branches, U.S. Geological Survey
PY  - 1972
DO  - 10.3133/ofr72406
UR  - https://pubs.usgs.gov/publication/ofr72406
ID  - ofr72406
ER  -