Solvability conditions of boundary value problems for quasielliptic systems

In the paper we consider boundary value problems for a class of quasielliptic systems in a half-space. The Lopatinskii condition is assumed to be satisfied. We establish sufficient conditions for the right-hand side of the systems under which the boundary value problems are solvable in $W_p^l(R_n^+)$, $1<p\leqslant p^*$.