“…In the case b ≡ 0 the unique global solvability of (1.1) and (1.2) (and (1.3) if ∂Ω ̸ = ∅) in Sobolev spaces is investigated by many authors, but is known only for small data in some class (for example, see [7,[2][3][4]15,18,13] in the whole space, and [14,8,21,22,10], in exterior domains in R n ). We prepare a class for the global solvability.…”