“…Boundary value problems for the Laplace, Poisson and Helmholtz equations with boundary conditions containing the higher order derivatives were studied in works by Bavrin [1], Karachik [2][3][4][5], Sokolovskii [6]. In the papers [7][8][9][10][11][12][13], boundary problems, including higher derivatives on the boundary, were studied for the Poisson, Helmholtz, and biharmonic equations. It should be noted that unlike our work, in the mentioned papers [1][2][3][4][5][6]14], the higher order derivative is given on the entire boundary.…”