%0 Journal Article %A Szymon Plewik %T Ideals of the second category %J Fundamenta Mathematicae %D 1991 %P 23-26 %V 138 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-138-1-23-26/ %R 10.4064/fm-138-1-23-26 %G en %F 10_4064_fm_138_1_23_26