TY - RPRT TI - Documentation of AIR3D, an adaptation of the ground-water-flow code MODFLOW to simulate three-dimensional air flow in the unsaturated zone AU - C.J. Joss AU - A. L. Baehr PY - 1995 DO - 10.3133/ofr94533 UR - https://pubs.usgs.gov/publication/ofr94533 ID - ofr94533 ER -