%0 Journal Article %A James Keesling %T Closed mappings which lower dimension %J Colloquium Mathematicum %D 1969 %P 237-241 %V 20 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-20-2-237-241/ %R 10.4064/cm-20-2-237-241 %G en %F 10_4064_cm_20_2_237_241