Douglas, Ronald G. Banach algebra techniques in operator theory Ronald G. Douglas - 2nd ed. - New York Springer-Verlag 1998 - xvi, 194p. - Graduate Texts in Mathematics . - Axler, S. . ISBN: 9780387983776 Subjects--Topical Terms: Operator theory Banach algebrasHilbert space Dewey Class. No.: 515.724 D745b2