- Anvar Irmatov, “On a new topology in the space of Fredholm operators”, Ann Glob Anal Geom, 7, no. 2, 1989, 93

- P. S. Popov, “A topological criterion for almost orthocomplementation of all functionals on ℓ2(C(X))”, Math Notes, 65, no. 4, 1999, 532

- E. V. Troitsky, “Geometry and topology of operators on HilbertC *-modules”, J Math Sci, 98, no. 2, 2000, 245

- Anwar A. Irmatov, Alexandr S. Mishchenko, “On Compact and Fredholm Operators over C*-algebras and a New Topology in the Space of Compact Operators”, J K-Theor, 2, no. 2, 2008, 329

- Петр Сергеевич Попов, Petr Sergeevich Popov, “Топологический критерий почти-ортодополняемости любого функционала на $\ell_2(C(X))$”, Матем. заметки, 65, no. 4, 1999, 636

- Peter Popov, Anna Buchina, “Quasi-Orthogonalization of Functionals on l2(A)”, Acta Applicandae Mathematicae, 68, no. 1-3, 2001, 123
