TY  - RPRT
TI  - Description of data files compiled for the Central Midwest Regional Aquifer-System Analysis
AU  - John O. Helgesen
AU  - Cristi V. Hansen
PY  - 1989
DO  - 10.3133/ofr8942
UR  - https://pubs.usgs.gov/publication/ofr8942
ID  - ofr8942
ER  -