TY - JOUR AU - S. Challal AU - Abdeslem Lyaghfouri TI - A filtration problem through a heterogeneous porous medium JO - Interfaces and free boundaries PY - 2004 SP - 55 EP - 79 VL - 6 IS - 1 UR - http://geodesic.mathdoc.fr/articles/10.4171/ifb/91/ DO - 10.4171/ifb/91 ID - 10_4171_ifb_91 ER -