%0 Journal Article
%A G. Ya. Perel'man
%A Petrunin
%T Extremal subsets in Aleksandrov spaces and the generalized Liberman theorem
%J Algebra i analiz
%D 1993
%P 242-256
%V 5
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AA_1993_5_1_a10/
%G ru
%F AA_1993_5_1_a10