%0 Journal Article %A A. A. Roǐtvarf %T A two-valued velocity field with a root singularity %J Vestnik Moskovskogo universiteta. Matematika, mehanika %D 1988 %P 41-44 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/VMUMM_1988_3_a10/ %G ru %F VMUMM_1988_3_a10