[886] The problem of unitary equivalence

[887] Elliptic systems in$H$_{$s,δ$}spaces on manifolds which are euclidean at infinity

[888] Unitary representations defined by boundary conditions—the case of sl(2,$R$)

[889] On bounded analytic functions and closure problems

[890] $K$-divisibility of the$K$-functional and Calderón couples