TY  - RPRT
TI  - Status of ground-water modeling in the U.S. Geological Survey
AU  - Charles A. Appel
AU  - J.D. Bredehoeft
PY  - 1976
DO  - 10.3133/cir737
UR  - https://pubs.usgs.gov/publication/cir737
ID  - cir737
ER  -