%0 Journal Article %A Zelinka, Bohdan %T Double covers and logics of graphs. II. %J Mathematica slovaca %D 1983 %P 329-334 %V 33 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/MASLO_1983__33_4_a0/ %G en %F MASLO_1983__33_4_a0