1. E. Albrecht and F. Vasilescu, Invariant subspaces for some families of unbounded subnormal operators, Glasgow Mathematical Journal, 45 (2003), 53–67.
2. L. Brown, Lidskii’s theorem in the type II case, in Geometric Methods in Operator Algebras (Kyoto, 1983), Pitman Research Notes in Mathematics Series, Vol. 123, Longman, Harlow, 1986, pp. 1–35.
3. J. Dixmier, Von Neumann Algebras, North-Holland Mathematical Library, Vol. 27, North-Holland, Amsterdam–New York, 1981.
4. P. Dodds, T. Dodds and B. de Pagter, Noncommutative Köthe duality, Transactions of the American Mathematical Society, 339 (1993), 717–750.
5. K. Dykema, Factoriality and Connes’ invariant T(M) for free products of von Neumann algebras, Journal für die Reine und Angewandte Mathematik, 450 (1994), 159–180.