%0 Journal Article %A S. E. Kholodovskii %T Filtration through strata with ring-shaped, nonhomogeneous, anisotropic zones, cracks and screens %J Doklady Akademii Nauk %D 1991 %P 606-608 %V 317 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1991_317_3_a22/ %G ru %F DAN_1991_317_3_a22