%0 Journal Article %A Andrzej Zarach %T Forcing with proper classes %J Fundamenta Mathematicae %D 1973 %P 1-27 %V 81 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-81-1-1-27/ %R 10.4064/fm-81-1-1-27 %G en %F 10_4064_fm_81_1_1_27