%0 Journal Article %A Ryszard Jerzy Pawlak %T On rings of Darboux functions %J Colloquium Mathematicum %D 1987 %P 289-300 %V 53 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4064/cm-53-2-289-300/ %R 10.4064/cm-53-2-289-300 %G en %F 10_4064_cm_53_2_289_300