%0 Journal Article %A J. Nagata %T On the countable sum of zero-dimensional metric spaces %J Fundamenta Mathematicae %D 1959 %P 1-14 %V 48 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/fm-48-1-1-14/ %R 10.4064/fm-48-1-1-14 %G en %F 10_4064_fm_48_1_1_14