TY  - BOOK
AU  - RITCHEY, Joseph D.
TI  - Subsurface Fluid - Flow ( Ground - Water and Vadose Zone ) Modeling
SN  - 0-8031-2021-4
U1  - 551.49011 
PY  - 1996///
CY  - USA
PB  - West Conshocken ASTM
ER  -