%0 Journal Article %A M. A. Almalahi %A M. S. Abdo %A S. K. Panchal %T Periodic boundary value problems for fractional implicit differential equations involving Hilfer fractional derivative %J Problemy analiza %D 2020 %P 16-44 %V 9 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/PA_2020_9_2_a1/ %G en %F PA_2020_9_2_a1