Resolvent Operator and Eigenfunctions of a Sturm-Liouville Type problem
  In this work we investigate the resolvent operator and completeness of eigenfunctions of a Sturm-Liouville problem with discontinuities at two points. The problem contains an eigenparameter in the one of boundary conditions. For operator-theoretic formulation of the considered problem we define an equivalent inner product in the Hilbert space and suitable self-adjoint lineer operator in it. 
Erdo\u{g}an \c{S}en, Oktay Mukhtarov, Kamil Oru\c{c}o\u{g}lu
math.SP