%0 Journal Article %A Eric van Douwen %A Teodor Przymusiński %T First countable and countable spaces all compactifications of which contain βN %J Fundamenta Mathematicae %D 1979 %P 229-234 %V 102 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-102-3-229-234/ %R 10.4064/fm-102-3-229-234 %G en %F 10_4064_fm_102_3_229_234