%0 Journal Article %A Hanan Shabana %T $D_2$-synchronization in nondeterministic automata %J Ural mathematical journal %D 2018 %P 99-110 %V 4 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/UMJ_2018_4_2_a10/ %G en %F UMJ_2018_4_2_a10