Herrero, Domingo A. Approximation of Hilbert space operators / Domingo A. Herrero - Boston : Pitman Advanced Pub. Program, 1982 - v. ; 25 cm. - Research notes in mathematics v.72 . Includes index Bibliography : p. 239-247 LCCN: 82-10163 Subjects--Topical Terms: Operator theoryHilbert space