%0 Journal Article %A I. E. Bashtanov %T Types of two-place relations and their preservation classes in three-valued logic %J Diskretnaya Matematika %D 1989 %P 86-96 %V 1 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/DM_1989_1_2_a8/ %G ru %F DM_1989_1_2_a8