On boundary values of solutions of elliptic equations degenerating on the boundary

Necessary and sufficient conditions are established for the existence, on the domain's boundary, of a limit in $\mathscr L_p$, $p>1$, of solutions of second order elliptic equations having Tricomi type degeneracy on the boundary.
Solvability of the Dirichlet problem for such an equation in spaces of type $W^1_{p,\mathrm{loc}}$ is proved.
Bibliography: 9 titles.