Akhiezer, N. I. 1901- Theory of linear operators in hilbert space / by N.I. Akhiezer and I.M. Glazman. Translated from the Russian by Merlynd Nestell. - New York Frederick Ungar Publishing Co. 1961 - 2 v. ; 25 cm. engrus Subjects--Topical Terms: Hilbert spaceLinear operators