“…The case when holes are distributed in the entire domain was addressed in [43,46,47] (Neumann conditions on the boundary of holes), [2,31] (Dirichlet conditions, also [2] treats Neumann holes), [30] (linear Robin conditions), [11,17] (Dirichlet and nonlinear Robin conditions). In [30,43,44] the holes are distributed periodically (in [31] -locally periodically), and are identical, while in [2,11,17] quite general assumptions on sizes and location of holes are imposed. The surface distribution of holes was treated in [15,18,19,24].…”