%0 Journal Article
%A I. A. Muzychuk
%T On the nonexistence of even 4-critical graphs of order~12
%J Diskretnaya Matematika
%D 1990
%P 47-59
%V 2
%N 4
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DM_1990_2_4_a4/
%G ru
%F DM_1990_2_4_a4