%0 Journal Article %A T. M. Atanacković %A S. Pilipović %A B. Stanković %T Weak solutions to differential equations with left and right fractional derivatives defined on ${\Bbb R}$ %J Bulletin de l'Académie serbe des sciences. Classe des sciences mathématiques et naturelles %D 2009 %P 75 - 88 %V 34 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/BASS_2009_34_1_a3/ %F BASS_2009_34_1_a3