00346nam a2200121Ia 4500082002000000100002200020245006200042260003500104300002800139490004700167500000500214700000500219  a515.72bB386.IO  aBeauzamy, Bernard  aIntroduction to operator theory and invariant subspacesb  aAmsterdambNorth-Hollandc1988  axiv, 358p. Index, Bibl.  aNorth-Holland Mathematical libraryv v. 42  a  a