S. Hosseiny Matikolai, “ON THE ANISOTROPIC BOUNDARY VALUE PROBLEM, CONNECTED WITH HELMHOLTZE-SCHRÖDINGER ЕQUATION, UNDER THE BOUNDARY CONDITIONS OF THE FIRST AND SECOND TYPE”, Proc. YSU A: Phys. Math. Sci., vol. 45, no. 1 (224), pp. 7–11, Feb. 2011.