%0 Journal Article %A A. S. Demidov %T On the evolution of a weak perturbation of a circle in the problem of a Hele–Shaw flow %J Trudy Matematicheskogo Instituta imeni V.A. Steklova %D 2002 %P 1212-1214 %V 57 %N 6 %U http://geodesic.mathdoc.fr/item/RM_2002_57_6_a5/ %G en %F RM_2002_57_6_a5