%0 Journal Article %A Jacob, N. %A Knopova, V. %T Fractional Derivatives and Fractional Powers as Tools in Understanding Wentzell Boundary Value Problems for Pseudo-Differential Operators Generating Markov Processes %J Fractional calculus and applied analysis %D 2005 %P 91-112 %V 8 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/FCAA_2005_8_2_a0/ %G en %F FCAA_2005_8_2_a0