%0 Journal Article %A Bachir, A. %A Segres, A. %T On the class operators. %J International Journal of Open Problems in Computer Science and Mathematics. IJOPCM %D 2009 %P 48 %V 2 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/IJOPCM_2009__2_1_225649/ %G en %F IJOPCM_2009__2_1_225649