TY  - RPRT
TI  - A modular three-dimensional finite-difference ground-water flow model
AU  - Michael G. McDonald
AU  - Arlen W. Harbaugh
PY  - 1988
DO  - 10.3133/twri06a1
UR  - https://pubs.usgs.gov/publication/twri06A1
ID  - twri06A1
ER  -