Free Download Unitary invariants in multivariable operator theor… By Gelu Popescu Publisher Amer Mathematical Society 2009 ISBN 0821843966,978-0-8218-4396-3..

Free Download Operator theory on noncommutative domains… By Gelu Popescu Publisher Amer Mathematical Society 2010 ISBN 0821847104,978-0-8218-4710-7..