TY  - RPRT
TI  - A modular three-dimensional finite-difference ground-water flow model
AU  - M.G. McDonald
AU  - A.W. Harbaugh
PY  - 1984
DO  - 10.3133/ofr83875
UR  - https://pubs.usgs.gov/publication/ofr83875
ID  - ofr83875
ER  -