%0 Journal Article %A O. V. Borodin %T Solution of problems of Kotzig and Grünbaum concerning the isolation of cycles in planar graphs %J Matematičeskie zametki %D 1989 %P 9-12 %V 46 %N 5 %U http://geodesic.mathdoc.fr/item/MZM_1989_46_5_a1/ %G ru %F MZM_1989_46_5_a1